Author Archives: Green Giant

Good Technique is the Path to the Perfect Hedge

With the first flush of spring growth well underway, it won’t be long before your hedges need trimming. Hedges are the basic architecture of many gardens, and the privacy and shelter they bring are essential for creating a personal garden space. Often they have a practical purpose, sheltering you from neighbors or traffic, but they also give form and structure, creating a stage for your plants to strut their stuff on.

Popular hedging plants like Thuja Green Giant have a natural density that makes it easy to grow them into solid green walls, but you also need to treat them right, and good hedges follow some simple rules for success.

Follow These Six Tips for the Perfect Hedge

Trim regularly – the more you trim, the denser it gets
Trim while your hedge is young – waiting till it reaches full-size is a mistake
Trim in the right seasons – too early, or too late, can cause problems
Slope the sides – an inward slope keeps the bottom green and healthy
Narrow the top – round or square, a narrow top sheds snow and ice
Feed and Water – like a lawn, you need to replace what you removed

Trim Regularly

Old-time gardeners don’t waste their words. They say, “The more you trim, the denser it gets”, and they are right. When you cut the tip off a growing stem, of any plant, it produces several new shoots a little below where you cut. Buds at the ends of stems produce a plant hormone that stops the dormant side buds lower down from growing. When you cut off that bud they are released from control, and spring into action. Think of how many tips you cut off with your trimmers going over a hedge. Multiply that by three or four, and you can see how many new stems you have. Many stems give us the crowded, dense growth that makes the perfect green wall. It really is that simple.

Trim from an Early Age

If there is one single mistake made when hedges are planted, this is the one. It seems logical that you would leave your hedging plants, like Thuja Green Giant, to grow to the size you want and then start trimming. But logic is not your friend on this one. A solid hedge that is resistant to wind and snow needs a strong internal structure of many short branches. Taking off just a little growth as your hedge is expanding will give you that sturdy structure. If you wait until it has grown taller, then all the density will be on an outside ‘skin’, and that makes your hedge vulnerable.

Start trimming as soon as you see new growth on your new hedge. Just take off an inch or so, regularly, and you will see how quickly it becomes solid. It will still grow up almost as quickly as if you left it alone, but this time you will have many branches, making a tough and sturdy hedge.

Trim in the Right Seasons

There is a rhythm to plant growth, and to the seasons. The longer days and warmer temperatures of spring trigger a big flush of growth, drawing on reserves stored in the previous year. The buds for that growth develop in late fall and early winter of the year before. So you need to let that first flush mature before trimming, as it is the new foliage that keeps your hedge dense and green. If you cut it all off, the older parts now have to make new buds to replace it, and the older leaves soon fall off, keeping the surface of your hedge always thin and weak.

To allow room for that new growth, without letting your hedge get bigger and bigger, you need to trim in fall, leaving all winter for the new buds to form. This also gives you perfect, tight hedges in winter, when they are especially prominent and visually important. When to make that last trim of the season depends on where you live. In colder area you should allow a full month before the normal beginning of cold temperatures and the chance of ice and snow – the odd morning frost is fine. That probably means mid-September is the latest time. In warmer areas you can trim later, often up to the end of November, depending on your climate.

Once the spring flush has started to darken in color, trim it, leaving a couple of inches of that fresh new growth. That trim will stimulate some more growth – a lot in a young hedge, less in an older one. How many times you cut between now and that vital fall trim, is up to you. At least once is usually necessary, and that will keep your hedge both neat and dense. For a super-hedge, make that two, one in early summer, and another in early fall, if you are in a warmer area.

Slope the Sides

This is another secret that is often ignored. The top growth of a plant is always more vigorous, and longer, than the lower growth. If you trim the same amount from all over your hedge, it will become fatter on the top, and narrower lower down. This will shade the lower parts and reduce their growth. In a short time the lower branches will die, and your hedge will be bare for several feet at the bottom – exactly where you want dense green growth.

So always slope the sides inwards just a little. You will be cutting more from the top than the bottom, but don’t worry about that. The less you cut from lower down, the better, as long as it is neat and flat. The best hedges have a flat side, like a sloping board, not a curve, and learn to keep that slope even all along the hedge – it is not difficult with a good quality, sharp hedge trimmer.

Keep the Top Narrow

Sloping the sides will naturally keep the top narrow, and that is something to encourage. A narrow top will shed snow and ice better, and the chance of your hedge collapsing is reduced greatly. With a narrow top you can keep it square and flat, if that suits your garden design, although rounding it for a less formal look is even better for shedding snow.

Feed and Water Regularly

Finally, trimming a hedge is like cutting the lawn. You remove material that is part of the strength of the tree, so hedges need more nutrients than untrimmed plants. Have a regular fertilizer program – organic or not, it’s your choice – and water during dry spells. It doesn’t take a lot of time, but that extra care, and the tips we have given, will make your hedge a stand-out feature of your garden.

Get Maximum Growth from Thuja Green Giant

There is a very good reason that Thuja Green Giant is the top-selling evergreen for hedges and screens – it’s growth rate. Proven in trials to grow faster than any other evergreen, during its early years you can expect growth of 3 feet a year or more, so that solid, tall plants will be yours in just a few short years. But plant growth is complex, and when rapid growth is not seen gardeners are understandably frustrated and look for answers. Let’s examine in detail the different factors that control the growth of those Thuja Green Giants you just planted or are thinking of planting.

Some of the factors that control the growth of plants are a given of their location and can’t really be controlled by us. Let’s start with those, as they alone can often answer the question, “Why aren’t my plants growing faster?”

Climate

Although we rely mostly on the USDA hardiness zones to look at this, these only measure winter low temperatures, and don’t take into account other factors, such as rainfall. How do these things control the growth of your plants?

Low Temperatures

Winter minimums for your zone are averages, and in bad years the real numbers can be much lower. Severe cold snaps kill many plants considered hardy in a zone, while in other, milder years borderline plants thrive. Thuja Green Giant is hardy throughout zone 5, but if there is a severe period of lower temperatures, they can suffer. Foliage may burn, so that plants in spring are now smaller than they were the previous fall. With evergreens, the ability to take up water from the ground all winter long is essential to keeping the foliage green, and especially if plants are new, and a lack of snow cover during a cold spell allows the ground to freeze, then foliage burn can easily follow, even in ‘safe’ zones. If you see dead leaves and burned foliage in spring, then a hard winter is often the simplest explanation.

As well, the amount of sunlight and dry winds in winter are a big factor in foliage burn. Cold dry winds and bright sun will cause damage at temperatures that will be just fine in humid, cloudy conditions.

Dry Summers

If you garden in a zone that typically has hot and dry summers, you will not see the same growth on your plants compared to places where they receive a regular water supply. Even watering cannot completely make up for those periods gardeners often call, ‘growing days’, when gentle rain encourages rapid growth. Only an Arizona-style full irrigation system can produce a lush oasis in hot, dry areas, and that is beyond the reach of most of us. So if growth happens mostly in spring and fall, with a long, dry, dormant summer period, you will not see as much growth on your Thuja Green Giant.

Wind

In exposed, windy places plants naturally respond by hunkering down, and creating broader forms, with shorter extension growth. Although Thuja Green Giant is often used for windbreaks – and it’s a good choice – the growth rate will be slower than in a sheltered area, which encourages the longest stem extension.

Location

Every garden is different, so your Thuja Green Giant plants may not have ended up in the perfect spot for maximum growth. There are two main limitations that can only be fixed in theory, since were we plant is often determined by the layout of our gardens.

Sunlight

Thuja Green Giant grows best and fastest in full sun, yet in gardens many places, including where you want a hedge, may be shaded, at least partly, by trees or buildings. Not only will the growth be slower, it will inevitably also be more open, and creating a dense, solid hedge will be more difficult. Like wind exposure, you can rarely control this, since a hedge has to go where a hedge is needed, so if there are significant periods between early spring and late fall where your hedge is in shade, the growth rate will be reduced.

Competition from Other Plants

While shade from surrounding plants is obvious, their underground activity is not, and we underestimate how far the roots of trees spread. Those planting holes you created, filled with good rich earth and fertilizer, are magnets for surrounding mature plants, which will have their roots into them in a couple of years. Thuja Green Giant will not grow at its maximum rate when it is fighting with tree roots for water and nutrients.

How to Improve the Growth Rate of Your Plants

All the above elements are pretty much out of our control, but there is lots we can do, with a little work, to get the best from our Thuja Green Giant plants, even if there are intrinsic limitations.

Soil Preparation

This is number one. Digging deeply, adding organic material and basic nutrients, as well as started micro-organisms, all give your plants the best possible start. This will be reflected in the speed they grow. Some people are disappointed when they do all this and still see limited growth during the first year after planting. Remember that until they spread out into that inviting soil, your new plants are dependent on the root ball that came out of the pot, so slower growth in the first year is, unfortunately, something we can do little about. The maximum period of growth for newly-planted trees is usually from year 2 to year 5, and it is during those establishment years you will see the biggest changes.

Watering

How, and how often, you water depends on where in the establishment cycle your Thuja Green Giant plants are. During that first year there are two goals. The first, basic one is to keep your plants alive, and that means keeping that root ball moist. A common mistake is to thing that if the soil looks damp everything is good. In reality your trees are at first dependent on that limited volume of root ball, so keep it moist by watering close to the stem.

Equally, you want to encourage your trees to spread their roots outwards, and they will only do that if the surrounding soil is moist. See that as a separate job, and keep the nearby soil damp, especially deeper down. Since a lot of root growth happens in fall, early winter and early spring, watch out for drought at those times, not just during spring and summer.

After that establishment period watering should be deep, and spaced out, so that the ground dries between watering, especially in the top few inches. You want to encourage deep rooting, so moisture needs to be lower down in the ground.

Fertilizer

For maximum growth, regular fertilizer application, either traditional or organic, is needed. This releases nutrients directly around the trees, so they have rapid access to them. In the first two or three years, liquid applications are best, as that really does get them down to the limited root area. After that, granular fertilizers work well, and they are a lot easier to use, especially if you opt for a slow-release type that only needs one application a year.

Grow Thuja Green Giant the Natural Way

Many people today want to grow their plants the natural way, without using synthetic chemicals and sprays, to protect themselves, their families, their community and the greater environment from harm. For decades we became so used to growing with fertilizers it can seem it must be hard to do it any other way. It isn’t. Let’s look at how you can grow hedges, screens and evergreen specimens of Thuja Green Giant, or any evergreen, successfully, without resorting to artificial methods using chemicals. Instead you can grow it naturally – the organic way.

The Power of Organic Material

In the natural world there is a great cycle of decay and renewal. Plants and animals begin their lives, grow, and then die. During that life they excrete the things they don’t need. That cycle is part of a great exchange of materials, between the complex chemicals that characterize living things, and the simple chemical elements of the rocks and soil. Between these things are the decomposers – fungi and bacteria that break down complex molecules into their simpler components. They take dead things – leaves, branches, fruits and roots of plants, and the waste from animals – and live on it, and in the process bring back the basic elements other plants need to grow.

We call that broken-down stuff, which still has further to go before it is completely returned to simple minerals, ‘organic material’. This can be garden compost we make ourselves, or that is made on a larger scale from city waste, or it can be the waste from farming. Animal manures from cows, horses and sheep are mixed with straw and turn into organic material. Plus, there are other sources of this valuable stuff, such as seaweed, or the waste left over when the oil is extracted from seeds like corn, soya or sunflowers. Even sawdust, if treated properly, can be used for this purpose.

This organic material is the basis for all organic growing, and fortunately, even if you don’t make your own garden compost, it is readily available in some form or other from garden centers and nurseries. So, if you are starting a hedge or screen with Thuja Green Giant, or if you already have plants you want to grow organically, the first step is to get yourself some.

Organic Material Works Miracles in Your Soil

What is so wonderful about organic material, and what sets it apart from artificial fertilizers is not the elements it contains. Every scientist will tell you – correctly – that the minerals it releases, such as Nitrogen, Potassium, or Iron, are exactly the same to the plant as a box of artificial fertilizer.

No, the secret of organic material lies not in its minerals but in what it does in the soil. Organic fertilizing is about feeding your soil, not your plants. If well-maintained your soil will do the feeding, from the vast mineral reserves locked up inside it. As well, organic material improves the physical structure and properties of your soil, making every soil more suitable for growing.

In clay soils, when we add the coarse pieces of organic material, we open up the structure of the soil, letting air in and water out. The enemies of plants in clay are just that – not enough air, and too much water. Roots need air and when it is excluded by too much water the roots suffer, become prone to disease and die. Clay soils usually have abundant chemical reserves in them, but these cannot be liberated for plants, because the airless, wet environment is unsuitable for the organisms that release them, and for the plant roots to find them. So digging organic material into the soil before planting Thuja Green Giant will open up your clay soil to good growth.

Amazingly, it works just as well in sand. There the problems are the opposite ones. Sandy soils don’t hold enough water for vigorous plant growth, and the rapid movement of water between the coarse soil particles removes nutrient minerals as fast as they are produced. Organic material holds more water, and it also acts as a bank account for minerals. As they are produced they bind to the material, so they are not lost, and the soil becomes richer and more nutritious.

So the practical lesson is, when planting, and as mulch each spring on young plants, organic material of almost any kind is your friend, and the key to growing Thuja Green Giant the natural organic way.

Feeding Young Trees

Now to access all those nutrients plants need an extensive root system. Young plants don’t have that, so they can use a hand to get going. The best way to do that the organic way is to use more concentrated sources of organic material. There are lots of these, but popular and reliable sources include poultry manure, decomposed feathers (rich in nitrogen), bone meal (for phosphorus) and alfalfa meal (another rich but gentle source of nitrogen).

As well, poor soil often lacks those microbes that do the work. These microscopic miracle workers take all that organic material and turn it into mineral elements, as well as releasing materials like gums and resins that bind the soil together into crumbly particles, creating the rich, healthy soil we want. There are several different materials on the market to kick-start both your soil and your plants. One good one is the Bio-Tone range, that includes a great ‘starter plus’ product for planting, which supplements your soil preparation and provides a solid base of microbe activity. This is especially important when you are starting a garden in disturbed soil, perhaps following construction. All that digging and soil moving disturbs the system, which needs to be restored or it can lay barren for a long time.

Once initial establishment is over, switch to a supplementary organic food, like seaweed emulsion, or another product, like Bio-Tone ‘Tree Tone’, which is designed for evergreens and trees, with a good nitrogen level for rapid growth and rich-green foliage.

Green Gardening is not Rocket Science

Growing Thuja Green Giant – or your other evergreens – in a natural, organic way is easy. Take care of your soil, and boost growth with the minerals released by the decomposition of organic materials, and you are there. You preserve the soil environment and improve it for growing plants at the same time. After all, these natural cycles have kept the planet green for millions of years, so harnessing them for our gardens is not rocket science. Good soil preparation and a steady, natural trickle of nutrients is all it takes – enjoy growing green!

Thuja Green Giant – Meet Mom and Dad

Thuja Green Giant is an evergreen conifer, widely planted for hedges and screens. Its vigor and reliability come from its hybrid parentage, marrying the best features of each parent, and masking their limitations.

Let’s look at those parent plants and see what features they have that produced this remarkable plant that has been planted in millions over the last few decades.

The Basic Story

Thuja Green Giant began its life in Denmark, at the Poulsen nursery in Denmark. This family nursery dated back to 1878, and it has once specialized in roses. In 1937 an unusual Thuja plant was found there, but because of the Second World War very little attention was paid to it. In 1967 the National Arboretum in Washington, D.C. bought a shipment of plants from Poulsen, to look for possibly valuable introductions for American gardens. Among that shipment were several Thuja plants, which were put out in a nursery to grow. By the 1990s, one plant was catching the attention of visiting nurserymen who were amazed to see it had grown 30 feet tall in just 25 years. They were given pieces to grow and test, and a nurseryman from Tennessee called Don Shadow suggested the name ‘Green Giant’ for the plant. A major grower – Wayland Gardens – produced many plants, and promoted it as a replacement for older, diseased hedges, and the rest, as they say, is history. But how this plant developed was at first a mystery.

DNA analysis was a new thing in the 1970s, but some scientists from the National Arboretum, The New York Botanical Gardens and the Holden Arboretum took on the challenge, and they found this plant was something that had never happened before – a hybrid between two species of Thuja, one from Japan and one from America. We don’t know how it came about – probably a chance cross-pollination – but the result was a demonstration of something well-known to plant breeders. They call it ‘hybrid vigor’, and it is seen in many of our food crops for example. When two closely-related plants are crossed together the strongest genes dominate, and most of the weaker ones are hidden. As a result, the offspring are far more reliable and vigorous than either parent. But our interest here is in Mom and Dad – the two parent species. Let’s look at them in more detail.

Japanese Arborvitae – Thuja standishii

Known as nezuko (クロベ ) in Japanese, this tree is an important timber tree in Japan. Light and soft, and therefore easy to work by hand, but durable, waterproof and pleasantly scented, it is used for sake kegs, tubs, and other bent-wood items. It is one of the Five Sacred Trees of Kiso, along with Sawara cypress, Hinoki cypress, umbrella pine and Hiba arborvitae. These were, and still are, the trees used to build Shinto shrines, temples and palaces, so for common people cutting one down was punishable by death.

Japanese Arborvitae grows 65 to 100 feet tall in the forests of Japan, with broad trunks up to 18 feet in diameter 4 feet above the ground. The foliage has a pleasant lemony smell, and in appearance it is typical of arborvitae. Only an expert can quickly tell one species of arborvitae from another.

This tree is found in southern Japan, mostly on the islands of Honshu and Shikoku. We might expect it to enjoy hot weather, but in fact it grows only at high altitudes, in mountainous areas up to 8,000 feet high. This means it grows well only in cooler, moist climates, an in North America it grows best in the northwest and northeast. It will not grow in dry areas, and in fact if you wanted to grow one it would be hard to find a plant except in a specialized nursery, or if you grew it from seed. If you live in a part of the country where it will grow, you might be able to find one at a local botanical garden or horticulture school in a college or university.

Western Redcedar – Thuja plicata

Since we don’t know how Thuja Green Giant came about, we don’t know for sure which plant Mom was – the seed parent, and which was Dad – the pollen parent. But it is nice to think that it might have been Western Redcedar, the rugged American meets the Geisha Girl. Sexual stereotypes aside, the American side of this meeting is not such a different plant, although much more widely known to the average American.

Even non-gardeners know the lumber called ‘red cedar’. Waterproof, and so very popular for outdoor construction, it has a well-deserved reputation as the lumber of choice for gardens. It needs no preservatives, and ages gracefully to a soft gray color, while weather brings out the grain in the surface, creating over the years that ‘lived in’ feel to the garden. Don’t confuse it with cheaper white cedar, from eastern arborvitae, Thuja occidentalis. That wood lacks much smell, and it is generally inferior. Red cedar has a very characteristic smell, of spicy decongestant chest rub, from the camphor in it, which fades over time.

Red cedar lumber is cut from the Western Redcedar tree, the other parent of Thuja Green Giant. This is an even taller tree than its Japanese cousin, and old trees approach 200 feet in height, and they can be 1,000 years old. The foliage when crushed smells like pineapple, and it has the same stringy reddish bark as the Japanese Arborvitae. It grows on both sides of the border between Canada and the USA in the northwest, and on Vancouver Island. In the US it grows through Oregon and Washington State. It also grows as a forest tree around the world, from Australia to Hawaii, and in Great Britain it has become a naturalized tree, spreading by itself. It grows along rivers and in the lush forests of those areas, kept constantly moist by rainfall in all seasons.

Like Japanese Arborvitae, you would have to search for a tree to plant, certainly outside of its native states. In Europe and Great Britain it is widely grown, especially for hedges, as the mild, damp climate suits it well.

Thuja Green Giant

So given the parents, both of which thrive only in damp, cool places, it is remarkable what a tough child they had. From zone 5 to zone 9, in a wide range of growing conditions, including drier zones, this reliable plant certainly shows us what hybrid vigor looks like in trees. For consistent rapid growth and reliability, it is still the number one choice almost everywhere.

Is Thuja Green Giant Right for My Garden?

When it comes to screens and hedges, the name ‘Thuja Green Giant’ is on everyone’s lips, but a hedge is a big decision you will live with for a long time, so let’s dissect that decision, so that you are sure this is the tree you want to be planting.

How Big a Plant do You Need?

Size matters, and untrimmed Thuja Green Giant are large plants, reaching 10 feet in 7 years in recorded trials in Arkansas, and ultimately growing more than 30 feet tall and 12 feet wide. Of course, trimmed regularly you can keep it under 10 feet tall, but if you want a hedge just 6 feet tall or less, and are prepared to wait a couple of extra years for it to mature, then there are a whole range of plants, from boxwood to Juniper, or for exactly the same look, Emerald Green Arborvitae, that will give you a great evergreen hedge that you can be more relaxed about trimming.

Of course, many people choose Thuja Green Giant exactly because it will become large. If you need screening from a highway, or some privacy from a neighboring tall building, then those extra feet are exactly what you want. Left unclipped the natural density of this tree makes for a solid barrier, and with regular trimming you can easily have 20-foot hedges if you want.

Where do You Live?

Thuja Green Giant is a tough plant, but it does have climatic limits. Its ideal growing range is between zone 5 and zone 8, and even into zone 9. That is a broad sweep across the nation, and if you are in those zones, then you will be making the right choice. But that does also leave a significant area where you might want to look to other hedging plants.

Considering the upper end first, it really depends on your exact climate. In damper zone 9 it will thrive, and certainly do better than Italian Cypress, which is often planted in Florida. There that tree will often suffer from fungal diseases, due to the humidity. In the same zone in the west – Arizona and southern California – Italian Cypress thrives, enjoying a similar climate to its southern European home, while Thuja Green Giant will find the extreme dryness a problem. So in humid, hot zones, stick with Thuja Green Giant, but in drier, drought-prone areas, you will find the Italian Cypress superior, unless you have excellent irrigation.

Looking north, there are significant parts of the country in zones 3 and 4, and even in zone 2. Sadly, if this is you, Thuja Green Giant is not for you. You can make excellent hedges however with its relative Thuja occidentalis, the arborvitae or white cedar. A top form for dense growth and ‘hedginess’ is Emerald Green Arborvitae. This plant is slower growing, and of course in colder areas the growing season is noticeably shorter. Since nothing beats Thuja Green Giant’s three feet a year plus growth rate when young, Emerald Green does still manage a respectable 18 inches a year in good growing conditions, so it will mature soon enough.

Do You Have Sun?

Like almost all evergreens, Thuja Green Giant is best when grown in sun. If you are looking at a partially shady spot for your planned hedge, then how many hours of direct sunlight does it get? Six hours a day, certainly in spring and summer, would be a minimum, and for a really dense hedge sun all day is best. If you have shade, then consider other possibilities for an evergreen hedge. The yew tree (Taxus) is the classic shade hedging plant, but boxwood is also a good choice. You might also move into broad-leaf evergreens, like English cherry laurel, or holly is also a good choice.

What is Your Soil Like?

Because it is a hybrid plant – a natural cross between two different species – Thuja Green Giant is tougher and more adaptable than either parent. So it grows well in almost all types of soil. From sand to clay, and in both acidic and alkaline soils, it does well. If you do have very sandy soil, prone to rapid drying, and lacking in nutrients, then the classic solution of adding plenty of rich organic material when planting is still the best solution. Using plenty of fertilizers may solve the nutrients shortage, but they will be rapidly lost, so you will need to do a lot of feeding. As well, they won’t tackle the water issues at all.

Organic material solves all three problems. It retains moisture, it provides a steady nutrient supply as it decomposes, and the humus created – a term for the long-term, very slow decaying parts of organic material – acts as a store for the mineral nutrients in the soil, preventing them from washing out in drainage water. An annual mulch with more of the same over the root zone will keep that soil in good shape, and reward you with rapid growth, and rich, deep green plants.

Not every garden is dry, and some suffer at the other end, with constantly wet soil. Perhaps you live in a low-lying area, or the place for this hedge is in a hollow. Maybe you are beside a stream or lake. Whatever the reason, if your soil is constantly wet then Thuja Green Giant will struggle. Most plants need oxygen at the roots, and wet soil is almost always low in oxygen, so roots are weak, and diseases easily attack them. The best strategy, and one that is often successful, is to mound up the earth in a long row, raising it at least 6 inches above the surrounding ground. If you do this by throwing up soil from trenches on either side, making the ridge at least 3 feet wide, and preferably wider, then you will also create natural drainage channels around your mound. Open them up for water run-off at the lower end, and you now have a well-drained planting area. It is some work, but the payoff is the great result. Now Thuja Green Giant will thrive, with good access to both water and oxygen around the roots. Problem solved.

Do You Have Deer?

Most Arborvitae are popular with deer as winter food, but Thuja Green Giant stands out as being deer resistant. This is not the same as ‘deer proof’, because of all grazing animals, deer are highly unpredictable. Young, inexperienced animals will test just about anything, and can damage plants even if they quickly give up. Very hungry deer, in the depths of winter, will eat just about anything too, so personal experiences can differ. Allowing for that, the consensus is that Thuja Green Giant is among the best of the deer resistant evergreens, so it’s a top choice is you are in an area where deer come around in winter.

Hopefully this run-down has been helpful in reaching a decision that will give you the best results. Thuja Green Giant is a great plant for many locations, but it is better to make a different choice than to make a wrong one.

So you planted a hedge last fall, you have just planted one in the last few weeks, or you are about to do it very soon. Congratulations – hopefully you chose something tough and fast-growing, like Thuja Green Giant, or in colder areas, Emerald Green Arborvitae. In very hot, dry areas you perhaps went with Italian Cypress, but whatever you chose, what happens in the first year after planting will set things up for the rest of your hedge’s life. Let’s see what you can do – nothing complex you can be sure – that will give your valuable new hedge the best start in life.

Prepare the Soil Well

If you have already planted your hedge, then this may be advice too late, but if not, then three things are important:

Dig Deeply – try to prepare the soil as deeply as possible. Try to go down 12 inches, mixing the soil, and adding suitable materials. For a single tree, prepare an area at least 3 feet across, or a line 3 feet wide for planting a hedge row. If you use a roto tiller, these machines can fool you into thinking you have done a great job, while in fact they just went over the surface. Go over two or three times, working the machine slowly, and letting it sink into the ground as far as it will go.
Add Organic Material – it doesn’t matter much what kind, just as long as you add it. A layer 2 to 4 inches deep is usually best, and garden compost, rotted farm manure, rotted leaves, even lawn clippings and fresh weeds, are all good materials to incorporate into the soil. These increase the water-holding capacity of light soils, increase the drainage and air content of heavy ones, and add nutrients and valuable microbes too.
Add Phosphates – this nutrient, needed for root growth, doesn’t move into the soil from the surface for many years, so it must be dug in to be effective. Sprinkling it on top after you plant is completely ineffective. You can use bone meal, superphosphate, or triple superphosphate, it really doesn’t matter, so consider cost. Sprinkle a layer over the soil before you add the organic material. You can’t damage your plants if you use too much, and a solid dusting is about right, so that it is clearly visible.

Water Regularly

This is so important, and basic, that it cannot be over-emphasized. New plants only have the soil that was in the pot to depend on, and in warm weather, or when growing vigorously, they soon use that up. It takes some time for roots to move out of this limited space and explore the surrounding soil. So when watering your new hedge, don’t use a spray and water the top only. Use a gently rain head, or a slow-running tap, and soak down close to the stem of each plant, letting the water run deeply down. This will keep your plants happy. You do also need to keep the surrounding soil moist, to tempt the roots to spread out, and this is why many smart gardeners put a ‘leaky pipe’ watering hose – the black, porous kind – down along their hedge. Weave it in and out of the stems, and let it run for a few hours, until the whole area is thoroughly watered. It does a great job, and also saves you the trouble of standing their watering.

Fertilize with Liquid Fertilizers

Feeding hedges is important. Like lawns they get clipped regularly, so foliage is lost, and it has to be replaced. This means more nutrients are used than by an untrimmed plant. Granular fertilizers are the easiest to use, and the most cost-effective, but young plants don’t have big root systems, so they can’t easily access the nutrients from these materials, which need time to migrate down into the soil. Far more effective is a liquid fertilizer, that carries the nutrients right down to the roots with the water. Choose something designed for evergreens, which will have lots of nitrogen to stimulate rapid growth. These fertilizers come as concentrated liquids – the easiest to use – or as a powder – the most economical. The only issue is that because they are dissolved in water, they cannot be very strong, so you need to re-feed every 2 weeks to a month. But for the first year they really make a noticeable difference in the growth rate and foliage density of your new plants, making them sturdy and strong. Stop feeding in early fall, to allow your trees to slow down and toughen up for the coming colder weather.

Start Trimming When Your Start Growing

When creating a hedge, we want a dense, twiggy structure, with lots of tight branching, to give you the solid structure that makes the most private hedge, the best looking one, and the one that resists winter breakage too. The single biggest mistake when people plant new hedges is to let it grow until it reaches the height you want, and then start trimming. This never gives the best structure. Far better is to trim lightly and regularly from day one. As soon as you see new growth, snip off the end inch of it. This will encourage the dense branching you want. It will also allow you to direct the growth upwards, not outwards, so that you have a slip hedge. Don’t forget to keep the upper part narrow, to encourage plenty of growth lower down. Once it gets going, trim very lightly once a month from spring to mid-fall.

Try to keep the front flat, but sloping slightly inwards, and the top horizontal – you might need some strings and a level to get started. Don’t trim at the very end of the season, especially in colder areas, as soft, young growth can suffer winter damage. In the end you won’t reduce the rate of growth significantly, as your new hedge works its way up to your target height, but you will have a great hedge as a reward for that bit of extra work.

This might seem like a very easy question to answer – just check the hardiness zone listed for it, put your zip code into the USDA map site, and there is the answer – right? Most sources list zone 5 as the coldest place to grow Thuja Green Giant, which means it is considered hardy to minus 20 degrees Fahrenheit (approximately minus 30 on the Centigrade scale, for all you scientifically-inclined gardeners – odd isn’t it, that we use metric money, but then use an ancient European temperature scale everyone else abandoned many, many years ago?). So that should settle the matter, and there is nothing else to talk about. . .

What About Wind Chill?

At this point someone is going to say that we have forgotten wind chill, that factor that separates two days at the same temperature into ‘tolerable’ and ‘brutal’ because of a howling northerly wind. Wind Chill certainly affects us, but not plants. Why? Because wind chill is a measure of how rapidly heat is drawn away from our bodies, something which happens because we are warm-blooded. Plants, on the other hand, are not, and their internal temperatures are basically the same as the surrounding atmosphere or soil. Apart from a few plants that grow so fast in spring – mostly bulbs – that they actually generate enough heat to melt their way through the snow, all plants are at the same temperature as the air, so Wind Chill is irrelevant to them.

Winter Burn

Wind does affect plants though, and it adds complications to just how hardy a plant can be. The usual advice given to gardeners about growing plants at the limits of their hardiness is to find a ‘sheltered spot’ in the garden for them. This usually means south-facing and protected by hardier plants from cold northern winds. This advice is of limited value, because what evergreens need protection from in winter is dry winds – whatever their temperature and direction. You may have seen the leaves plants in summer shrivel and burn in hot, drying winds, but although direct sun may play a part, it is the dryness of wind that matters. We may feel a hot summer wind as dry or damp, but in winter all winds are relatively dry.

This is because the amount of water the air can hold increases with temperature. Yes, many people don’t realize that a cold winter wind is much, much drier than a balmy summer breeze. For example, at 100 degrees Fahrenheit the air can carry over 50 grams of water in a cubic meter. At 50 degrees that falls to less than 10, and at 32 degrees less than 5. By the time we reach minus 20, the hardiness limit for Thuja Green Giant, it holds just 1 gram of water. Larger amounts turn into dew, mist, fog or rain. Winter air is very, very dry.

How does this effect plants? Water is constantly being lost from the leaves and foliage of plants, by a process called transpiration. That water must be replaced from the roots, and when the ground freezes that cannot happen. So over time the foliage loses more water than it can replace, leading to drying, and the effect we call ‘winter burn’. In evergreens, this is the primary factor controlling hardiness. The other is the ability of roots to resist cold. Since soil is much warmer than the air, roots have much less cold-resistance than stems and branches. This is why plants left in pots outdoors die in winter, but the same plant in the ground will survive perfectly well.

What Does this Mean for Thuja Green Giant?

What all this means in the end is that if you can either increase the ability of the roots to take up more water, and/or reduce the amount of water lost from the leaves, then Thuja Green Giant can resist lower temperatures than usually suggested. Also, if you neglect these factors, it can easily die, even in zone 5. This is true for all plants, but especially for evergreens, which are vulnerable, because they carry their leaves into winter. From a practical point of view, this weakness is going to be worse in younger plants, so if you can keep your plants growing until they reach a good size, they are much more likely to survive in the long-term. So how about some tips for doing that?

Protecting Thuja Green Giant from Winter Cold

There are three ways to protect Thuja Green Giant, and other evergreens, from cold winter temperatures, especially when they are young.

Encourage Deep Root Growth

Deeper soil is warmer and doesn’t freeze. (How deep your soil freezes depends on where you live, of course.) The deeper the roots of your trees go, the more water they can continue to reach in winter, and the less their risk of winter burn. When you prepare the soil for planting, try to dig it as deeply as possible, so that the roots have plenty of soil to grow down into.

Water Your Trees in Late Fall

This is a very effective way to protect against winter damage. Let a hose run gently for several hours over the root zone of your trees, so that the soil is thoroughly wet. Do this as close to freeze-up as you can. Increasing the water content of the soil around the roots does two things. Obviously, it puts more water near the roots, so they can take up plenty. More subtly, it increases the specific heat of the soil, so it takes more winter cold to make it freeze. Specific heat is the amount of energy needed to change the temperature of something. It takes five times as much heat to warm wet soil as against dry soil. so that when the cold penetrates, we can think of it as being ‘used up’ in the top few inches, instead of freezing down a foot or two. The deeper roots can still get at liquid water and keep the foliage moist.

Mulch your trees

Besides its other properties, mulch is a good insulator. Soil covered with mulch, especially plant-based mulches, not stones, will freeze much less, and often not at all. Once you have completed that late-season watering, mulch around your trees too.

Use Anti-desiccant Spray

Widely used by professionals, but neglected by home gardeners, these products, which are entirely natural and made from an extract of pine trees, cover the foliage with a protective coating that reduces dramatically the rate of water loss. They have an equally dramatic effect on survival, especially helpful with new planting, and reduce or often eliminate winter burn, even on vulnerable plants at the limits of their hardiness.

So How Hardy is Thuja Green Giant?

You can see the picture is complex. The bottom line is that if you help your young trees in the ways suggested here, their survival is going to be greatly improved. In zone 5, and even into zone 4, your trees will leave winter as healthy as they entered it, and you can push the hardiness significantly – this is indeed a tough plant.

After a hard winter, it time to get out and explore the garden, to see how it survived, and if anything is needed. For hedges in particular, winter can be tough, especially if there has been heavy snow, freezing rain, or storms. As well, there are things to do that will give you the best results in the coming growing season, so let’s look at some things you can do that will fire up your hedge for a great season of growth and development. These things are especially important if you planted a hedge last year, in spring or in fall.

Check for Broken Branches

The weight of snow, ice, or simply strong winds can all break branches, especially on older hedges that have perhaps not been trimmed correctly. They may not always be obvious, although of course sometimes they are all too obvious! The main issue when removing broken branches from evergreens is that most conifer evergreens, like Thuja Green Giant, Emerald Green Arborvitae, Cypress, and others similar plants, is that they cannot regenerate from old wood. That is, branches that don’t have some green shoots on them. So hopefully leaving a thick branch, thinking it will re-sprout, as most trees do, is never going to work. If a breakage has happened below the green parts of the tree, then remove it neatly right back to the main limb it is growing from.

When cutting, leave the collar of bark you will see just where the branch joins on – don’t cut flush. The cut will be bigger with a flush-cut, and take longer to grow bark over, but more importantly, it is likely to cause die-back into the stem and leave permanent damage and weakness. This, by the way, applies to all limb removal from every kind of tree or shrub.

When you have cut away all the damaged parts you can assess your hedge. If you trimmed from an early age you should have lots of branches surrounding the gaping hole where that limb came out, and you will be surprised how quickly even large holes fill in. Smaller gaps will be gone in half a season, larger ones might take two seasons, but go they will.

If however the damage is to the end of a hedge – perhaps a snow-plough ran into it, for example – it is much harder to repair, and there it makes much more sense to take out the last tree entirely, dig the area well, and plant a good-sized replacement.

Mulch Your Hedge

If your hedge is young, or old and showing yellowing and slow growth, then mulch is very beneficial. Use something rich and nutritious, like garden compost or rotted animal manures (cow, sheep or horse) rather than bark chips or shredded bark. Yes, those hard materials last a long time, and they do conserve water and suppress weeds, but they don’t supply any nutrients. Richer organic materials release lots of nutrients as they break down, and for an older hedge they really will rejuvenate it over a few months. For young hedges too, the benefits are terrific, with better soil properties, more beneficial microbial activity in your soil, and nutrients too.

When mulching, keep the material clear of the stems, and don’t bury the foliage either, as it will soon die and brown if it isn’t exposed to light. A layer 2 to 4 inches deep in about right. You don’t need to remove all the old leaves and clippings which often accumulate under hedges, as they will also break down once you had some rich compost.

Fertilize Your Hedge

By far the most important thing to do in spring, especially for a young hedge, is to fertilize it. You can find both older-style chemical fertilizers, and organic-style ones too, and organic ones are especially useful for poorer soils, and of course they don’t involve energy-intensive manufacturing from fossil fuels either. To the plant it makes no difference – by the time they are ready to be absorbed by the roots they have been turned into basic elemental forms – plants don’t absorb vitamins or other complex molecules, since they make them all themselves.

There are three main kinds of fertilizers suitable for hedges – liquid fertilizer, granular fertilizers, and slow-release fertilizers. All three have their uses. Immediately after planting, and for the first season, you will get the best results using liquid fertilizers. These are sold either as concentrated liquids, or powders. Powders are much more economical, and easy to use – just dissolve the recommended amount in water. Young plants have limited root systems, and liquid fertilizers flow right down into the root ball, so they are easily and quickly absorbed, but they need regular application – once a month or even once every two weeks – for best results, as they cannot be concentrated, or the roots will burn.

In the longer term applying liquid fertilizers takes too much time, so after the first season or two, switch to granular forms. These are also more economical. The ordinary types are applied in early spring, mid-summer and early fall. Follow the directions for the amount to apply. Slow-release forms, which look like tiny pebbles, are more expensive, but they only need to be put down once a year. Choose which to use depending on your budget and how much time you have available. Fertilizer in sticks which you drive into the ground is usually not ideal, as it may burn the roots near it, and not spread well to areas further away, producing uneven growth.

Formulations

The fertilizer market is crowded, with many brands all competing for our attention. Forget all that, and instead go straight to the fertilizer formula – the 3 numbers (20-20-20, for example) required by law to be somewhere on the box or bag. If the first number is noticeably bigger than the next two, then that will be fine for a hedge. Even lawn food works on a hedge, although it is not ideal, since it has too much nitrogen (the first number) and not enough of the other nutrients. You want something balanced, but with more nitrogen than anything else. Other nutrients are optional extras, unless you have very sandy soil, where micronutrients can be scarce. If you mulch with that rich organic material we mentioned, then all you need is the nitrogen boost for rapid growth, so don’t worry about the fancy stuff. Check out our blog pages for more detailed blogs on fertilizing hedges.

Watering

In some areas early spring can be dry, with little rain. If that is happening, don’t forget to water your hedge deeply, especially a young hedge. A lot of the annual growth takes place in spring and early summer, and dryness will seriously reduce that, so don’t forget to water.

With spring arriving across the country – sooner in some places than others – planting time has arrived, and many people will be planting hedges and specimens of America’s most popular evergreen, Thuja Green Giant. This fast-growing tree is the top choice for taller hedges and screening, but when faced with that shipment of plant, sitting in their pots, some new gardeners may not be too clear on the best way to plant them, so let’s consider that. After all, getting plants off to a good start is always the first secret of success, and equally, a bad start can set you up for poor results, and even failure.

Prepare the Ground

Although we don’t see it, the life of plants below the ground is at least at important to them as what goes on above ground. Scientists have laboriously excavated the root-systems of plants from grasses to big trees, and in every case the roots occupy a vastly bigger volume than the above-ground parts. Many times bigger. So it follows that we should give it just as much attention, since we want to see much faster growth than a tree is nature will achieve. Most young seedling trees sprouting in the wild die, and those that don’t usually struggle for years to gain a foothold, but in gardens we want rapid growth and establishment from Day One. To do it properly you need two things when preparing the soil for your Thuja Green Giant plants – organic material and a source of phosphates.

Organic material

The exact type you use is not so important, but adding it is. No matter if your soil is sandy, clay, or something in between, the magic of organic material always improves any soil. Sandy soils retain more moisture and nutrients, and clay soils (which usually have lots of nutrients already) develop better drainage and more vital air penetration into the soil. You can use garden compost if you have it, rotted leaves, old potting soil from planters, rotted farm or stable manure, or even peat moss (which despite its popularity is not such a good choice). If you are planting a single tree, you need about a bucket full, and if it is a row for a hedge, you need a layer 2 or 3 inches deep, over an area 3 feet wide.

Phosphate

Of the three major plant nutrients (nitrogen, phosphate, and potash) you only need to add phosphate when preparing the ground. Why? Because this nutrient doesn’t move around in the ground easily, so if you sprinkle it on top it will quite literally take years and years to work its way down to where the roots are. All other nutrients are quickly carried down into the soil by watering or by rain.

There are several good sources of this, and most gardeners know bone meal. Expensive for a big job, its great for a couple of trees. Otherwise track down some superphosphate (or triple superphosphate, which is a bit stronger) and use that – it does the job at lower cost. A heavy sprinkling of this – like a light snowfall – should go down before digging, and in poor soil as some more as you go too. You can’t hurt your plants with too much, and it stays in the ground for many years.

Digging

Scatter the phosphates and then spread the organic material on the ground before digging or rototilling, which should then be done as deeply as you can go. For a row, prepare a strip at least 3 feet wide, or 5 feet wide if you are planting a double row. For an individual plant, dig an area at least 3 times the width of the pot, and again, go deep. Then level of the surface and leave it to settle for a few days before planting, if you can. If it was dry when you dug, setting up a sprinkler and giving the area a thorough watering is also a good thing to do.

Planting

Now to get down to the real job. The night before you plant, give the trees in their containers a good watering, soaking the soil. Never plant a dry tree, because it can be hard to get the root-ball wet after planting is over. Doing it the night before will mean it is not soggy on the day, and easier to handle than a freshly-watered tree.

You will have worked out the spacing for your plants, as we went into in detail in this previous blog, so set out your plants according to your plan. With hedges and screens, the best future look requires careful, even spacing, so put some time into adjusting this until you are satisfied. Use a stretched string to get the row straight.

If you have prepared the planting spot well you will only need to dig holes a little wider than the pot – just enough to be able to easily plant. Dig the holes where you have placed each plant, to the same depth as the pot only. Leave the tree standing next to each hole.

Preparing the Root Ball

Some people find the next step surprising, and hesitate to do it, because they are fearful of damaging the plant. Don’t be. This is an important step in helping your trees become established quickly and preventing future problems with roots strangling the growing trunk of your trees – a problem called ‘girdling’. It is similar to what you may have seen with trees tied to tightly to a pole – the rope cuts into the bark, and it can kill the tree. Roots wrapped around inside the pot can do the same thing as they and the trunk grow larger. Preventing this is important, so don’t be afraid for the tree.

Slide your Thuja Green Giant out of the pot. Take a sharp box-cutter and make 3 or 4 deep cuts from top to bottom around the root ball, going in about one inch deep. This will cut through the girdling roots.

Into the Ground

Now it is time to finish, and this is the easy bit. Sit the tree in the hole. Use a short stick laid across the top of the hole to adjust the position so that the top of the soil in the pot is level with the soil surface. Don’t bury deeply, and if your ground is poorly-drained, raise it up an inch or two above ground level. Now push back some soil, and using your foot, firm it down around the roots. Once you have about two-thirds of the soil back, fill the hole to the top with water. While it drains down, move on to the next tree. Once the water has drained away, put back the rest of the soil, firming it gently down. Rack the surface level, and you are done – no need to add more water, although if you want to you can.

To finish, mulch over the root balls with an inch or two or organic material, keeping it away from the trunk and foliage.

That’s it! You have given your Thuja Green Giant trees the best possible start for their life in your garden.

Deciding on the trees to use for screens and hedges is a big decision. Not only are these features going to set the form of your garden, and give you the privacy and protection you need, you will make a significant investment in them, so you want to get it right. Let’s look at why choosing Thuja Green Giant is going to be the right choice for almost all situations.

Why Choose Thuja Green Giant

For Fast Growth – 3, 4, or even 5 feet a year in the early years
For Year-round Green – stays green and healthy-looking all winter long
For Health and Vigor – its hybrid nature ensures super-vigorous and healthy growth
For Adaptability – grows well in many different soils and hardiness zones
For Easy Care – trouble-free, and after establishment takes care of itself

Choose Thuja Green Giant Because It Grows So Fast

The rapid growth of Thuja Green Giant, especially when young, has been proven in independent University trials. It grows faster than any other hedging evergreen we know off, adding up to 4 feet a year in the early years. Usually it will grow less the first summer after you plant it, although if planted in spring and cared for it will often be well established by the first fall. It is in the 3 or 4 years following that period of establishment is when you will the fastest growth, with your plants adding 3 or 4, or in exceptional circumstances even 5 feet a year.

This means that in those first few years, when you are anxious for the promise of privacy and screening to actually happen, Thuja Green Giant delivers. By the time you have had your trees in the ground for five years you can realistically expect them to add 10 feet or more to the height they were when you planted them. After that, growth with slow down, and adding two feet a year, and later just one, is normal. This is great, because by then your plants will be the size you want them, and slower growth means less trimming is needed.

Speaking of trimming, for screening you don’t even need to do it, although an occasional shaping helps keep your trees extra neat. Unlike many other fast-growing plants, Thuja Green Giant doesn’t begin to fall apart in a few years. Instead, it stays dense and tight, resisting wind, snow and storms, and always looking great.

Choose Thuja Green Giant because it is always Green

A common issue with a lot of evergreen hedges is discoloration in winter. A hedge should be fresh and green, but a lot of the plants used can and do turn bronzy-brown in winter, once some serious cold arrives. Yes, they do green up again in spring, but it does mean that they look dull and even unsightly in the winter months. At that time we want to see something green, to keep our hopes up for the coming spring. This is where Thuja Green Giant stands out from the others. It really does live up to its name, and your plants stay green and lush throughout the coldest parts of the winter. We don’t know about the ‘Jolly’ part, but the ‘Green’ part is certainly true!

Choose Thuja Green Giant for Health and Vigor

The last thing we want in our gardens is problems with hedges. They are meant to stay in the background, look good, and need limited attention. This is not always the case with some of the plants used. For example, older plantings of Leyland Cypress have been attacked by diseases in some areas, and other evergreens can also suddenly decide to start dying. Thuja Green Giant became so popular so quickly precisely because it stays healthy, and it keeps growing vigorously in many different locations and soils. It grows well in all kinds of soil, from sandy soils to clay soils, and in everything in between. It doesn’t like to be growing in soil that is constantly wet, but even then, if you plant your hedge or screen on a raised ridge of soil, up to 12 inches above the surrounding soil level, it will grow well in difficult, wet sites too.

It is also remarkably pest and disease resistant, because it is a hybrid plant, and plant breeders have known for years that when we cross two different species or forms that are related, the resulting plant is tougher and more vigorous than either of its parents. They call this ‘hybrid vigor’, and Thuja Green Giant has it in spades.

Choose Thuja Green Giant for Adaption to Different Locations

When planting hedges and screens, we don’t want plants that are choosy about where they live. With Thuja Green Giant we don’t have those problems. It is hardy all the way from zone 5 to 8, and even into zone 9 in drier climates. You might live in the rainy north-west; the hot and humid south- east; the colder north-east; or all across the open mid-west. It really doesn’t matter to this tree, because it is vigorous and adaptable enough to thrive almost everywhere. North America has an enormous range of climates, but growers in almost all of them tell us that Thuja Green Giant is thriving there. Even in coastal areas this is one of the best choices for everywhere short of right on the beach, because it is more salt-resistant than other arborvitae (Thuja) trees are. So no matter where you garden, you can be pretty sure that this is the best plant to choose.

Choose Thuja Green Giant for Easy Care

Finally, we don’t want to be fussy about our hedges, and they should not need a lot of regular attention. Thuja Green Giant doesn’t. It is of course best to give it some TLC in the first year or two, paying attention to watering it regularly, planting it into well-prepared soil, and using fertilizer to maximize the growth during those critical early years. Regular trimming right from the beginning is recommended too, for a hedge, as that builds a strong internal structure that will keep it healthy and lush right to the ground for life. But after that small push in the early stages, Thuja Green Giant, like children we have raised successfully, can stand on their own feet from then on, and really only need to be trimmed once or twice a year, depending on how neat or natural you want your planting to screening to be. You can see from all this, that for all the right reasons, choosing Thuja Green Giant is the right choice for almost every garden, almost everywhere.