Hybrid Vigor and Thuja Green Giant

Anyone who has planted Thuja Green Giant, or seen its rapid growth, even in difficult conditions, will have realized what a remarkable plant this is. Many will have asked themselves why this would be – what makes this plant stand out among so many others? The reason lies in the origins, and genetic nature of this plant, so to understand it more, and see why it is that such a plant can exist, let’s look at the whole concept of hybrids and why so many of them have such special properties.

What is a Hybrid Plant?

A common mistake is to call these plants ‘High-bred’, thinking that the word means they have been bred in special ways to a certain high point – rather like the way we breed racehorses or prize-winning dogs. Although this certainly gets at the value of these plants, it does not accurately reflect how they have been created.

There is a big difference between plants and animals, and it is this. Because animals can move around and interact with other animals, there are barriers against one species breeding with another. Although this does happen, as with mules (horses bred with donkeys) or ligers (lions bred with tigers), it is very rare. Plants cannot move around, however, so these barriers are not common among them, and it is often easy for one species of plant to cross with another. In nature different plant species grow many miles apart, so crossing can never happen, and there is no reason for mechanisms to develop that would prevent it. Once plants from different places are brought together in a garden, there is often very little to prevent closely-related plants crossing. Our garden are full of hybrid plants, and many of them came about because plants from different places were suddenly being grown together

A hybrid plant is one with parents that are two different species. They usually share the same ‘first’, or genus name, but the ‘second’, or species name is different.

The Parents of Thuja Green Giant

For Thuja Green Giant, one parent is Western Redcedar, called by botanists Thuja plicata. The second parent is Japanese Arborvitae, called Thuja standishii. Notice that the first name is the same for both of these plants, but the second, species name, is different. This is common for all hybrid plants – crosses between a plant from one genus with a plant from another are very rare indeed.

Western Redcedar is a close relative of the White Cedar (Thuja occidentalis), which is also known as Eastern Arborvitae. Together these plants grow from one side of North America to the other, fromhe Pacific to the Atlantic. While White Cedar grows no more than 50 feet tall, and usually a lot less, Western Redcedar can grow to 200 feet, and it easily forms a tall tree. It is a relatively fast-growing tree, adding as much as two feet to its height each year when young.

Japanese Thuja, also called Japanese Arborvitae, grows high in the mountains of Japan, but it is only rarely grown in gardens. It grows between 60 and 100 feet tall, and looks a lot like Western Redcedar.

Notice that these two plants grow thousands of miles apart – 4,700 miles to be precise. There is absolutely no chance that they could ever naturally meet, and breed. So when they were grown near each other, as happened in a nursery in Denmark back in 1937, there was nothing to stop them crossing, and a seedling growing from that event. The resulting plant, which was spotted by the nursery owners and put aside as something interesting, took another 60 years to be seriously noticed, and analyzed. Using modern DNA analysis, scientists at the National Arboretum were able to establish that this interesting Thuja really was a true hybrid between those two parent plants, coming from opposite sides of the Pacific Ocean.

Hybrid Vigor Develops

What is remarkable about Thuja Green Giant is that it is tougher and faster growing that either parent. This is possible because as most people know, genes come in pairs (well, when did you see a pair of Levis with just one leg?). Over time, some bad genes accumulate in plants, slowing down their growth, and making them more susceptible to pests and diseases. If these bad genes are just one of the pair, then that is usually OK. It is when they become both parts of the pair that problems develop. When individual plants continue to cross within one species for thousands of years, it is inevitable that some bad genes will become ‘normal’ among some of the thousands of gene pairs.

However, when hybrids happen, a good gene from one plant replaces one of the bad genes, and each pair gets a new good gene – hiding the effect of the bad ones. So the hybrid plant has lots and lots of great genes, and the bad ones don’t show – the plant can really give its full potential. Since each plant will have its own, unique, bad genes, they will usually be different from the bad ones in the other plant. So each parent gives strong good genes to the hybrid plant, and they ‘mask’ the bad ones of the other parent.

Plant breeders have known about this for a very long time, because they have seen it happen with corn, food plants, and many other plants too. So while we may be surprised at the vigor and growth-rate of Thuja Green Giant, experienced plant breeders aren’t. They know the virtues of hybrid vigor when they see it.

The Vigor of Thuja Green Giant

We only have to notice the growth rate of this remarkable hybrid to see hybrid vigor at work. While the parent plants grow at the very most 2 feet a year, Thuja Green Giant easily manages 3 feet or more – 50% faster – with very little trouble. Even faster rates have been recorded in young plants, so we can safely say the hybrid vigor doubles the growth rate.

That is just a beginning. While both parent plants are a bit ‘fussy’ about where they grow, Thuja Green Giant grows well in all kinds of soils, be they sand or clay, wet or dry. So strong is the hybrid vigor effect, that we have here a plant the will outgrow any other conifer on the planet, and produce a long-lived, hardy tree that is pest and disease resistant too. Even deer stay away.


So when you are thinking about hedging plants, you hardly need to think further than Thuja Green Giant. Hybrid vigor really works, and this plant is living proof of that.

Is Your New Hedge Ready for Winter?

So you recently invested in a new hedge – probably Thuja Green Giant, since that is the most popular hedging plant across most of the country. Perhaps you planted it back in the spring, or maybe it was more recent, and you took advantage of some of the price deals around and planted in September. So you are probably looking at your plants right now and feeling a bit concerned that winter is coming. You don’t want to be looking at a row of dead plants when spring rolls round again. Don’t worry, it won’t happen, at least not if you take a few simple steps to give your plants the best chance of surviving. Let’s look at some key things that will make sure spring brings you a perfect row of plants, ready to take off and grow you the perfect hedge.

Trim Your Hedge in Fall

If you planted in spring you perhaps have not trimmed yet. Maybe you are thinking the best thing to do is wait until the plants reach the size you want, and then start trimming. That is definitely not the right thing to do, as trimming should be on your ‘to do’ list right from the beginning. Taking off an inch or two regularly will build a solid, dense structure and give you the best hedge when it does reach its ideal height. It will also make keeping it at that height easier.

As for going into winter, a neatly trimmed hedge will resist wind and snow damage much more successfully than if it is overgrown, with branches shooting in all directions.

So take out your hedge trimmer, and go lightly over the hedge, removing longer shoots and taking the tips off, so that it looks neat. Leave the bottom wider than the top – that is, slope the sides inwards by a few degrees, and take more from the top than the bottom. You want to keep that bottom growing strongly, and narrowing the top is the best way to do that. While a dead straight side profile might appeal to you, that slight lean inwards actually looks very neat, and is the right way to do it. When you are done, don’t forget to clean and sharpen your trimmer before putting it away for the winter.

Fertilize Your Hedge in Fall

Using a fertilizer designed for fall application is always a great idea to set your hedge up for winter. These blends contain less nitrogen, so they don’t cause a big burst of growth, that could be damaged by colder weather. They should contain more potassium than normal. You can check this by looking at the last of the three numbers on the bag that show the analysis of the fertilizer. It should be at least half the first number, which is nitrogen. More than that is fine too.

Potassium makes strong cell walls, and raises the mineral levels in the cells. This acts like anti-freeze, protecting against cold injury, and the thicker walls protect against insects and diseases. Potassium also makes the stems stronger, so they are less likely to be blown over, or bent by the weight of snow. Of course, Thuja Green Giant is not likely at all to be attacked by pests or diseases, but a little protection never hurts.

Water Your Hedge in Fall

Now we come to the most important thing of all – watering. If you live somewhere where the ground freezes in winter, more than an inch or two deep, then your evergreens are at risk of winter injury. This is especially so with newly-planted material, such as that new hedge we are working to protect. Here is the thing – evergreen foliage continues to lose water in winter, even though it is not growing. In fact, because the air is very dry in winter, compared to summer, your plants lose a lot of water, especially when a cold, dry wind is blowing. That water must be replaced from the roots, but if the soil is frozen, then so is the water in it, and those plant roots are trying to suck an ice-cube, and are not getting much water from it. So the foliage dries out, and in spring, as soon as the temperatures rise, it turns brown, which we call ‘winter burn’.

The solution is to make sure that those roots have as much water as possible available to them. That way the foliage is not already dry when the coldest weather arrives. As well, that water in the soil slows down hard freeze, so there is still some ‘free’ water around for the roots to take up. So, water every week or two, from early September until freeze-up – your hedge will love you for it, and you will love the fresh green foliage on your hedge when spring comes.

Mulch Your Hedge in Fall

Covering the soil at the roots is also an excellent job for fall. If your hedge is newly-planted, the you may have done this when you planted it. If there is still a good layer, then you are set to go. If not, then a couple of inches of organic mulch will do the trick. Cover the ground out from the hedge, as the roots may already have begun to spread, but keep the mulch off the stems. Something rich and organic is better than bark, and bark is better than stones, but of course what you use will depend on what is available, and the look you want in your garden. Mulch will conserve water, and it will insulate the ground, reducing freezing, and so protect further from winter burn.

Protect Your Hedge in Fall

One of the last jobs of the season is to give your new hedge some protection, depending on where it is located. If it is along a road or driveway, and salt is used, then there is a risk of salt damage to the foliage. Thuja Green Giant has good tolerance of salt spray, but when young, even that tough plant will benefit from some protection.

There are two ways to go. If the risk of salt damage is fairly low, then an anti-desiccant spray will do the trick. These sprays put an invisible plastic coating over the foliage, keeping salty water away, as well as protecting against winter burn by reducing evaporation from the foliage. The second choice is the traditional burlap screen. This is a roll of burlap attached to poles and strung in-between the source of the salt and the hedge. Make sure it is taller than your hedge, and keep it at least 6 inches away from the foliage. Some people make the mistake of putting it right on the hedge, but if it becomes soaked with salty spray, then you are going to make the problem worse, not better.


If you do these simple things, your beautiful new hedge is going to look just as beautiful in spring, and you can look forward to years of beauty from it – especially if you made the wise choice of Thuja Green Giant.

Fastest Tree on Roots – Thuja Green Giant

Seems like we live in an age of speed – everything happens faster – instant messages, instant email, instant meals – and our gardens are in on the trend too. There was a time when we were patient enough to wait years for hedges of yew or hemlock to grow, but today we want our hedges fast, not slow. It often seems that when we need something, along it comes, and with hedges too, over the years, new plants have been introduced that give us the faster growth we are looking for.

The first super-fast hedging evergreen to come along was the Leyland Cypress. This plant has a long and complex history, dating back to 1888, at a grand estate in the British Isles. It took many years for this unique plant to be noticed, and although it became popular for hedges in England in the 1930’s, it was the 1950s and 60s before it arrived in America. Its distribution by Clemson University in South Carolina at that time made it hugely popular in the southern states – even more popular than in Europe. The arrival of this fast-growing plant coincided with the expansion of cities and the growth of suburbs, and it became the ‘go-to’ plant for privacy and screening between the new homes spreading across the landscape.

Leyland Cypress remains justifiably popular, but over time the plants become very large, especially if they are not regularly trimmed. So many hedges simply became too large, and after 30 years or so, there was a need to replace them. As well, in hot places some disease problems developed, making it necessary to find a substitute. Anyway, for practical reasons, it always makes sense to replace an old plant with something different – using the same plant can result in poor growth.

It was at this point – just when it was needed – that Thuja Green Giant came along. Although this tree had first been found in Denmark, the Second World War prevented it being introduced into America until 1967. A single plant was growing at the National Arboretum in Washington DC, but it was only in the 1990s, when that plant had reached an impressive size, that it began to attract attention. Several nurserymen who visited the Arboretum wanted to grow this remarkable plant, and they were given pieces to root and grow. The name ‘Green Giant’ was dreamed up by a nurseryman from Tennessee called Don Shadow, and that great name certainly helped to draw attention to this terrific plant.

There were several things about Thuja Green Giant that got those nurserymen excited. The first was its speed of growth. Young plants grow as much as 3 feet in a year, and sometimes even more. As plants mature they slow down, but in 7 years a 10-foot hedge is virtually guaranteed from the smallest plant, and obviously if you start with 3, 4, or 5-foot trees, they will double in size in just a few years. Nothing else approaches that – not even Leyland Cypress.

What is the secret to this rapid growth? It happens because this plant is a hybrid between two natural species of Thuja – the Japanese Thuja (Thuja standishi) and Western Redcedar (Thuja plicata). Neither of these plants is particularly fast growing. When they get together, however, we see what scientists call ‘hybrid vigor’ – offspring that are stronger, faster-growing and generally tougher than either parent.

Because it is not only in speed of growth that Thuja Green Giant excels, and shows this hybrid vigor. Other kinds of cedar are likely to show browning in winter, but not this one. Others may be particular about the soil they grow in, but not this one. Others suffer from pests and diseases that can make them unsightly, or have preferences for particular soils, but no, not Thuja Green Giant. It doesn’t really matter what kind of soil you have – sand or clay are all suitable, and so are acid or alkaline soils. Dry or wet, all soils are suitable. Only if your soil is regularly flooded can this great plant not be grown. It is very rare to see any kind of pests or diseases on it either, and even if you do it will be very minor and cause no particular concern.

Now if course this tree is a fantastic grower, but it does benefit from some attention. In particular, good soil preparation will give it the best start in life. This means digging the soil well, by hand or with a roto-tiller. It also means adding organic material, like compost, rotted manure or peat-moss to the soil. Some starter fertilizer is an excellent idea too. These basics will give your plants a great start – and give you those growth rates you are looking for.

So will regular watering, especially during the first season or two, while your plants become established. If you are really keen to see the maximum growth this plant is capable off, make sure it doesn’t become dry, and use a liquid hedge food regularly, according to the directions of the particular one you use. Don’t make the mistake of thinking, “If some is good, more is better.” That rule does not apply to feeding your plants – too much can bring problems.

The third way to get the most from your new hedge is to trim it right from the start. “Wait a minute,” I can hear you say, “How can it grow tall if I keep clipping it?” Well you are only going to remove an inch or two each time, so it will hardly affect the height at all. The reason for clipping from the start is to build a dense, twiggy structure to your hedge. Keeping it tight, and building a strong structure will make a hedge that can resist strong winds, snow, and ice. You see, the only problem with this plant is that it cannot produce new, green growth from thick woody stems. As a result, you cannot cut it back if it gets too large. If you have to cut a large amount off, you will have a thin structure that will only very slowly recover and become dense. By trimming a little, but often, you will never have that problem, and you will keep a neat, dense hedge of the size you want for many, many years.

Thuja Green Giant has been planted in the millions, by millions of satisfied gardeners, and it remains the number one choice everywhere it can be grown. If you garden in zones 5 to 8, and you need an evergreen hedge that is 6 feet tall or more, then choose the Green Giant – you won’t be disappointed.

Prepare Your Hedge for Winter

If you live in cooler parts of the country, then winter can be rough on a hedge. Since there is not much else to see in the garden, hedges become much more prominent at that time too, so their appearance becomes more important. With the risk of storms increasing, and a mood of uncertainty in the weather, no matter where you are, taking steps to protect your hedges from damage makes a lot of sense.

Prepare Your Hedge for Winter

  • Choose the right hedging plants – Thuja Green Giant for zones 5 to 8, Emerald Green Arborvitae in colder regions
  • Water well through the fall – even if rain has fallen, soaking the roots protects against winter burn
  • Apply fall fertilizers – use something designed for fall, with high potash for cold-resistance
  • Trim your hedge in fall – a trimming in September will create a tight structure and reduce the risk of damage from snow, ice or strong winds

Correct Choice of suitable Hedging Plants

If you are still in the design-phase of your hedge, then some careful consideration of what plants to use makes sense. Across most of the country Thuja Green Giant is the most popular pick, by a long way. Not only is it fast-growing, it is tough and reliable, and stays a fresh green color all year round. Great as this plant is for hedges, it is hardy just to zone 5, and if you are on the northern limits of that zone, and certainly if you are anywhere in zone 4, then it may not be the right choice for you. Winter lows below minus 20 degrees are the cut-off point. If you are likely to have nights below that, then Emerald Green Arborvitae is the best choice. This plant is hardy all the way down to minus 40, so there are few places in the country where it won’t come through the winter untouched. It is a bit slower growing, and it can sometimes bronze a little in winter, but if you live in cold areas, it is the right choice – an outstanding hedging plant for cold places.

On the other hand, once you are well into zone 5, and certainly all the way up to zone 9, Thuja Green Giant has to be the top, number-one choice for everyone who needs speed, lush green growth, and reliability across a wide range of soil conditions.

Keep up the Water Supply

Although we associate fall with rain, sometimes it doesn’t come, or at least not in great quantities. Because of their overhang, hedges keep light rain away from their own roots, and it is easy for your hedge to be dry when colder weather arrives. Dryness at the roots is without doubt the single greatest cause of winter damage in evergreens. Once the ground freezes, the roots can no longer bring up water to the green parts. Exposed to the cold, dry winds of winter, and also to the warming and drying effects of winter sun, that foliage will dry out, without the moisture being replaced. When spring comes, suddenly you are looking at dried-out foliage on your hedge.

If you do one thing for your hedge before winter, make it a good soaking at the roots, or even a couple, separated by two or three weeks. Even if you have had some rain, it never hurts to get lots of water onto the roots, especially of a newly-planted hedge. Not only does the water in the soil slow-down freezing, it ensures that the leaves are fully hydrated when winter comes. Some of the water may not freeze, so the roots will still be able to supply the foliage with enough to prevent winter burn and death. Keep soaking right up to freeze-up, whenever that comes for you. You won’t regret the little bit of work involved. If you run a soaker hose along the line of your hedge, it will make the job very easy, and it will be useful in summer too, when periods of drought arrive.

Use a Fall Fertilizer

You might think fertilizing your hedge in fall is a bad idea, but it isn’t. You need to use a suitable fertilizer – check your local garden center or hardware store for something labelled for fall use on hedges. These have lower levels of nitrogen, so they don’t stimulate new growth. They also have elevated levels of potash (Potassium), which helps cells pump the maximum amount of water into the foliage, stimulating thicker cell walls. This in turn brings greater resistance to cold, diseases and insect attack too. Sometimes the nitrogen is ‘packaged’ in a form that sits dormant over winter, and then becomes available as the soil warms, which is a fantastic way to get spring fertilizer to your plants as soon as they begin to grow. These products have many benefits, and should be used more by home gardeners. Always follow the manufacturer’s directions for application, and use early in the fall, generally before early October.

Trim Your Hedge for Winter

When it comes to protecting your hedge against damage from snow and ice, or strong winds, nothing works as well as trimming in early fall. The hedge that is a little overgrown, with areas where snow or ice can lodge, or with branches that can be whipped around by strong winds, is the hedge that suffers winter damage. The more you trim, the tighter your hedge will grow, and it is that dense, tight growth that sheds snow, and filters the wind, keeping your hedge from injury. Thuja Green Giant is fast-growing, so to build a strong structure it needs regular trimming. Always trim in all directions across the face of the hedge. If you only trim upwards – a common mistake by beginners – you will encourage long branches on the face of the hedge. These are easily dislodged by wind, and then broken, leaving large gaps that can take several years to fill in. Cut downwards as well as upwards, to create horizontal, tufted branches that stay tight in the hedge, preserving a solid, unbroken face.

When trimming the top, if you get significant winter snowfall, then a rounded shape, on a narrow top, will shed snow, and ice much better than the classic square top. Square works well if you are zones 8 or 9, where snow is a rare or non-existent event, but regular snow calls for the protection of a rounded top.

Just make sure you do this important job early on in the season. The end of September is the deadline in most areas – but mid-October is fine in warmer zones. Any later and you may create soft new growth that is more prone to winter damage.


These few simple steps will greatly increase the likelihood that come spring, you will have a perfect hedge, ready to go for another season. Hedges are great backdrops for any garden, and they deserve a little attention to help them along.

Fall Trimming of Thuja Green Giant

The Labor Day weekend marks the turning point of the year between summer and fall. September is an important month in the garden, with preparations for the following year on the calendar. Besides planting trees and shrubs, and of course some spring bulbs, a careful and thorough hedge trimming is recommended. You want your Thuja Green Giant hedges to go into winter not only looking good, but with the best chances of coming through the winter in perfect condition. If you only trim once a year, this is the time to do it. With that in mind, let’s look at some suggestions to achieve that perfect trim, and give yourself the best hedge in your neighborhood.

Tips for Fall Hedge Trimming

  • Sharpen Your Trimmer – you will get the perfect cut
  • Slope the Sides – a gentle inward slope keeps growth right to the ground
  • Round the Top – a rounded top will shed snow and ice, preventing breakage
  • Trim the Face in all Directions – don’t encourage long, upward-growing branches
  • Never Cut to a Leafless Branch – new growth can only come from green branches
  • Apply a Fall Fertilizer – this will toughen your plants, and keep them green all winter

Sharpen Your Trimmer

A sharp trimmer makes a clean cut, leaving no ragged edges to turn brown. Although you have to look closely to even see those brown edges, when they are all over your hedge they destroy the lush green look you strive for. Sharp trimmers greatly reduce that browning, as well as making the whole job so much easier.

There are two choices. You can take your trimmer to a professional dealership, preferably for the brand you own, and have your trimmer cleaned, adjusted and sharpened. Since they have sharpening machines, the result will be a trimmer that cuts like the first day you used it.

If you don’t want to do that, or your trimmer is only a little blunted, then you can do the job yourself. First, clean the blades, to remove dirt and dried-on resin and sap. You may need a solvent to do that – alcohol or petrol both work well. Use a brush to loosen the dirt, and rinse off petrol with soapy water. Then you are ready to sharpen.

You need a flat file with a fine grain, and a sharpening stone. Begin by filing the blades. Move the file in the direction of the blade, and keep the same angle as the blade is already sharpened at. Only file areas that already have an edge, and don’t file too much. Do the same amount of filing on each blade – just a few strokes will do it. Now pass the sharpening stone flat across the bottom of the blade, to remove the burr. Brush the teeth with a stiff brush to remove filings, and apply an anti-rust spray. Job done!

Set the Angle of Your Hedge

An important part of creating a durable, long-lived Thuja Green Giant hedge is establishing a gentle slope to the sides. The upper part of a hedge will always grow more vigorously, and eventually starve the lower parts, as well as weakening them from the shade created by the top. To keep your hedge thick and green right to the ground, you need to slope the sides inwards by a few degrees. This doesn’t have to be noticeable, but it should be enough to let the light right down to the bottom. You can use a long pole and a level to visualize an inwards slope, or you can make a wooden triangle, with one side sloping backwards by a few degrees. That will give you a consistent guide, which is very useful for a long hedge. If you can see your hedge from its end, then you will be able to see the angle clearly, and see where you need to trim more.

Round the Top of Your Hedge

While it is possible to maintain a flat top, as long as you keep it narrow, for most hedges it is easiest to shape the top into a semi-circle. This will shed snow effectively, preventing breakage under the weight of snow and ice, something that will quickly destroy a beautiful hedge. Keep the top thin, no more than 12 inches wide, as a thick top is much more likely to lodge snow, and break open. If your top is thin, then you also know that you have got that sloping side right.

You should also try to keep the top level, or if you are on a steep slope, cut into in several sections, with a neat drop in height for each one. Sloping tops just look weird and untidy, and won’t give your garden the quality finish you want.

Trim Your Hedge Horizontally

A big mistake of many novice hedge trimmers is to only use the trimmers going upwards. This encourages long, upright branches on the face of the hedge, rather like a comb-over on a balding head. This might make the hedge look lush, but those long branches are vulnerable to damage, and they are easily loosened by wind and storms. They end up hanging outside the hedge, and often breaking, leaving a large gap that can take several years to fill.

Much better is to pass the trimmers in all directions across the face of the hedge – upwards, downwards and sideways. This will encourage short, horizontal branches, with dense, tufted ends forming the green parts of the hedge. These are much more durable, and if one does die, it doesn’t leave a large hole, but a small one that will fill in a single season or less.

Never Cut into Leafless Branches

Sometimes you see hedges which have clearly not been trimmed for several years. In an attempt to reduce the height or thickness, someone has cut the branches back to bare stumps. Never, ever do this! If you do, those branches will not grow back. Like most evergreens, Thuja Green Giant cannot produce new green growth from a bare stump, only from thinner branches that still have some green, leafy parts to them. This is a good reason to trim your hedge at least once a year, or you will find it very hard to reduce its height of width, and it will soon grow larger than you wanted it to be.

Use a Fall Fertilizer

Ideally, you want your hedge to produce just a little new growth after the final trimming – enough to make it look green and lush, but still neat and tidy. To do this, try to trim about 6 weeks before the temperatures falls below 40 degrees, when most growth stops. When you trim, also apply a fertilizer designed for fall application to hedges. These are usually available in garden centers and stores at this season. They contain higher levels of potassium, which strengthens the cell walls, making them more resistant to cold. This reduces the risk of any winter browning, and also makes stems that are more resistant to being pushed over by wind or storms. As well, some of these fertilizers contain nitrogen in a form that is only released in warm weather. So it sits in the soil until spring, ready to feed the first flush of growth. There will also be a small amount of nitrogen to give a quick flush of new fall growth, making your Thuja Green Giant hedge look green and lush all winter long.

Fall – The Best Time to Plant Thuja Green Giant

Still the most popular hedging and screening plant around, Thuja Green Giant really gives its best in your garden. For a reliable, fast-growing and tough hedge, it can’t be beaten. When you have made the decision to plant this terrific evergreen, then timing is important, and the question of when is the best time of year often comes up from beginner gardeners.

With plants growing in pots, it is possible to plant any time the ground is not frozen, and deciding when may not be a matter of choice – you need that hedge, and you need it now. The availability of potted plants makes that possible, None the less, there are good times, and not-so-good times to plant. The middle of summer, with its heat and dryness, is probably the worst time, as you will need to be watering almost constantly, and root-growth into the surrounding soil will be minimal. As for the best time, there is really no doubt, it is early fall. Let’s see why that is.

The Soil is Warm and Moist

We often say that when it comes to plants, ‘it’s the soil, stupid!’ With fall planting, that is certainly true. Fall often begins with an extended period of rain, and falling onto soil that is hot from the summer, the result is moist, warm soil – ideal for the growth of roots. Contrast that with spring planting, when the soil is cold and wet. If you live in areas where the frost goes deep into the ground, you might even have frozen layers still below the surface in spring, so you are effectively planting onto an ice pack. In that environment, water moves slowly, and there is little oxygen in the soil. Dangerous microbes thrive in these low-oxygen conditions, and they can attack the young roots of your Thuja Green Giant, setting up a struggle for survival that certainly slows down the establishment of your plants.

In that warm, moist fall ground, good microbes are active, releasing nutrients, and protecting your plants. The roots divide and divide rapidly, and if you have prepared the ground well, they quickly penetrate deep into the ground.

The Air is Cool

In contrast, the air temperatures of fall are low, especially at night, and it is a fact that the roots of your Thuja Green Giant grow well in temperatures that would stop the top growth all together. The top is prevented from growing by the cool air, so all the energy of the plant goes into establishing a wide and deep root system.

In spring the opposite is true. Then the ground is so cold that even roots don’t want to grow, yet the warm days stimulate new shoots. It is easy to make the mistake of thinking that rapid growth of new leaves means your plant is doing well. If it is newly-planted, that may not really be true. Sooner or later the roots will have to catch up, or the top growth will suffer. If you have a spring heat-wave and drought, something that is common, then it is easy for the roots to dry out, fail to supply the leaves with enough water, and we see die-back. At the very least, you will have a lot of work keeping your new hedge watered. In fall, those first rains are almost always followed by more, so a steady moist soil is yours, with no work needed.

There is Plenty of Time

The most common cause of poor establishment in spring is the rapid arrival of summer. Spring planting is often a narrow window, between frozen ground and summer drought. Spring flowers know that – which is why they burst out of the ground and flower so quickly. There is no time to spare. If you are a bit late in planting, or summer comes early, then your plants are not established, and you are facing a summer of endless watering, not what you want at all.

In fall, we are pretty much guaranteed a couple of months of mild, damp weather. This gives your plants plenty of time to establish their roots, without facing drought or heat. Obviously a much better situation for good establishment.

What about Winter?

At this point somebody will be thinking, “But won’t my plants suffer in winter, if I plant them in fall?” This is a common idea, but one that is not true. If you live in a zone where Thuja Green Giant has no problem with winter (which would be zone 5), then neither will young plants. The earlier in fall you plant, the better – September beats November, without a doubt. The secret is to allow enough time for the roots to spread out and establish themselves, before soil temperatures get close to freezing, and root growth stops. But you have a big window, depending on where exactly you are – certainly from Labor Day to mid-October, and usually all the way to Halloween. Just a few weeks, under these ideal conditions for root growth, is all it takes.

If you do find yourself delayed, and don’t plant until close to freeze-up, then spray your plants with an anti-desiccant coating, just to be sure. These treatments are excellent for evergreens, and they protect from winter-burn very effectively. Use them even on established evergreens if you want to see perfect green in spring, particularly in colder regions.

Ready for Spring

The greatest thing of all about fall planting is that by spring, your plants will be ready to take off – and put on lots of strong new growth. They will have the root-development to support vigorous stem extension and a dramatic increase in height.

Thuja Green Giants that are well-established when spring arrives can take advantage of the season to really get going, and they will take the summer much better too. You can pretty much guarantee that the same size plants, one batch planted in September, and the other in April, will not make the same growth. By the end of their first summer the ones planted in fall will be significantly taller and bushier than their spring-planted equals. It is from plants such as these that the measurements of over 3 feet in growth a year are taken. Fall planted, well-established by spring, and fertilized and watered as needed.

Save Money Too

Oh, there is one more thing. Nurseries often put their plants on sale in fall. So there are really substantial savings to be had. Plus, many sellers offer free shipping. As well, the plants you receive have already had a season being cared for by the nursery, so they are solidly the height advertised, and you get an extra ‘growth bonus’ too.


Taken together, all these factors tell us that fall planting of Thuja Green Giant is the way to go. If you are planning a hedge, but thought you would wait till spring, think again, get your order in, and plant in fall. You won’t regret it.

Instant Hedge, or Let It Grow?

The decision to start small and grow a hedge from young plants, or invest in larger plants and get an instant result, is a perennial question the comes up with Thuja Green Giant, and other hedging plants as well. There is no ‘one answer fits all’, but there are certainly several considerations that help guide the decision. Let’s look at some of the issues, and the best way to handle your plants – big or small.

Growth Rate and Cost

It is obviously cheaper to plant a hedge with smaller plants, and the great thing is, that with Thuja Green Giant, the growth rate of young plants is high – they slow down as they get older. Young trees that are 1 to 3 feet tall might grow 3 or even 4 feet in the second year after planting – or in the first one if you plant in late winter. So they will often ‘catch up’ with larger plants. After 7 years, your small plants will be 10 feet tall, or more, and the ones you planted when they were big might easily be not much taller. That growth rate was demonstrated at the University of Arkansas, so it really is a reliable and accurate figure.

Privacy Issues

Instant privacy is the usual reason for investing in large plants, in the 5 to 6-foot range. You know how it goes – you move into a new home, or perhaps a new one goes up next to you, and suddenly you are overlooked by neighbors. We all love our neighbors, but we don’t really want to become a reality TV-show for them, so the desire for privacy is natural. With 6-foot trees, you instantly gain privacy from anyone walking on the ground, and even from most ground-floor windows. The extra cost is often worth it, for the peace of mind you gain by an instant solution.

On the other hand, if you don’t have an urgent need, then plant something smaller – they won’t take long to catch up, as we have already discussed. Use the money you save to buy beautiful and interesting shrubs and trees to decorate that beautiful private space you are creating with your Thuja Green Giants. Those trees and shrubs will grow along with your hedge, and in a few short years you will have a beautiful private garden to enjoy.

Planting Larger Thuja Green Giant Trees

When planting larger trees, there are some things to pay more attention to, so that you get the best and quickest establishment, and the fastest growth to add more feet to your hedge or screen. First, dig a wide area of ground for them. Three feet wide is not too much. One of the mistakes often made is to dig holes just big enough to take the root-ball, with little or nowhere broken up for the roots to grow into. This is a big mistake, and will certainly slow down growth very much. Instead, use a tiller to save yourself the work of hand-digging, and prepare an area 12 inches deep and 36 to 48 inches across. Add plenty of organic material, and a starter fertilizer as well. Break up the ground thoroughly, but don’t try to bring in new soil. That is almost always a mistake – put the effort instead into top-quality organic material, and dig in a layer 3 or 4 inches deep.

When you plant bigger trees, it is best to dig a trench the width of the pots all along the planting area, rather than dig individual holes. You can more easily get the spacing even that way, and even spacing will give you a solid hedge quickly. Make sure to water the trees well the day before, and use a sharp knife to cut an inch or so into the root ball at three points around the root-ball and in a cross on the bottom, after you carefully remove the pot. Place the plants in the trench right away, and don’t lift them by the stems, lift the root ball, or you may cause it to break apart. Water thoroughly.

Big trees will benefit from regular watering and liquid fertilizers during the first year, and always water the surrounding soil, not just at the stem, so that the roots quickly spread outwards.

Planting Smaller Thuja Green Giant

If you are using trees in the 1 to 4-foot range, the most common mistake is to plant them too closely together. Use the same spacing, no matter what size your trees are. If you buy a lot of small trees, and crowd them together, many will die, and the strongest will be slowed down by the smaller ones, that act like ‘weeds’ and steal water and nutrients. Over time they will naturally thin out, but not in the neat way you might like – more like a mouth of broken teeth!

Even though your trees are small, still prepare the wide area we have already described. You want the roots to spread out and find water and nutrients from the surrounding soil, and they can do that best in well-prepared soil.

The best spacing depends on the final goal. If you plan on keeping your hedge around 8 feet tall or less, then a 3-foot spacing is best. Those small plants are going to look too far apart, but really, this is the right thing to do. Without competition from each other they will grow wider, taller and be much healthier. They will grow so fast, before you know it they will be touching each other and building a strong screen for you. For a taller screen, use a 4 or 5 foot spacing. A double row, with 3 feet between the rows, and 5 to 8 feet between the plants, depending on the final height, will give you the thickest and densest hedge possible.

Young trees have small root systems, so they really benefit from regular applications of a suitable liquid hedge fertilizer. Follow the directions on the brand you buy, and apply from spring to early fall, at the frequency recommended. With most liquid fertilizers, you can safely increase the frequency if you reduce the concentration. Double the frequency, but half the concentration is the usual rule. That way you provide a steadier supply of nutrients, and you will have taller, bushier plants by the end of the season.


Whatever your choice – big or small – you can be sure that if you have chosen Thuja Green Giant for your hedge or screen, the result is going to be a gorgeous, healthy hedge or screen, rich green all year round, tough and reliable, and the perfect backdrop and privacy barrier for your garden.

Cordless Hedge Trimmer Review

Almost everyone plants Thuja Green Giant as a hedge, or a screen. Trimming is part of the routine of keeping your hedges neat and tidy, and to do that well, a power trimmer is a great addition to your arsenal of gardening tools. It is worth buying a good-quality unit, as the savings in time and frustration will soon cover any extra dollars involved.

Traditionally, the choices were between gasoline and electric trimmers, but today there are machines on the market that bring some interesting new options. If you have used a gasoline trimmer, then you know about the noise and smell they create. Added to that is a growing awareness of the environmental impact of the CO2 emissions as well. So while gasoline has the advantage of portability, these issues mean that gas trimmers are not as desirable as they once were.

The second choice was electric, but the long cord trailing across the yard is always a problem, especially when you end up cutting it, bringing your trimming, and often all other household activities as well, to an abrupt halt. The relative peace and quiet were always a good quality, but that darned cord is a serious issue.

In the past few years, as batteries have come to be used in more and more of our household items, battery trimmers have hit the market. These offer portability and quiet operation, but do they have the power and endurance needed for all but the smallest hedge?

While prices have fallen a lot since their initial introduction, they still remain higher than for conventional trimmers, so you want to be sure you are getting value for money. What are the key features to look for?


Right away, you should choose a trimmer with a Lithium battery, not a nickel-cadmium one, if you want reasonable endurance for your trimmer. Most Thuja Green Giant hedges are substantial, so you will need the extended time to get the job done in one go. If you trim a lot in one day, then having a spare battery, or one that will re-charge in less than an hour, is a way of extending your time on a smaller machine, so make sure you can by the battery separately.

Bar Length

A longer cutting bar has two advantages. It cuts a bigger area, so you finish the job more quickly. It also gives you more reach, so when trimming higher up, or doing the top, you can reach farther without such a tall ladder, and you need to move the ladder more often. All these things add up to faster, more efficient trimming, so go for the longest bar you can. 24 inches is idea, but you may end up trading a few inches in return for a better machine.

Weight and Balance

The big drawback with lithium-battery trimmers is the weight, which comes mainly from the battery itself. It’s impossible at this stage of the technology to have both light-weight and a powerful cutter, so be aware that you will be holding a heavier trimmer. Smaller machines weigh in at around 6 pounds, and the weight rises to almost 12 pounds in the most powerful ones. On a power basis, they are usually lighter than a gas machine, but heavier than an electric. Think too about where the battery is positioned, since you are waving a trimmer around a lot, and you need good balance to make that less tiring.

Let’s look at four top trimmers and see how they stand up:

BLACK+DECKER LHT2220 20V Lithium Ion Hedge Trimmer, 22″

This is the top-selling trimmer on Amazon, and with a price well below $100, it deserves its position. However the battery only has an estimated running time of 40 minutes, so it really only works for boxwood hedges and individual shrubs around the garden. A large hedge is beyond its ability. The slightly more expensive LHT321FF has a more powerful battery, dubbed the ‘Powercommand’, and offers longer life, but still the limitation of only 20 volts.


This is a more powerful trimmer, with a larger, 40 volt battery that will trim both sides of a 300-foot hedge, 10 feet tall, on a single charge. Not only that, but the battery charges in one hour, so while you stop for lunch you can bring it back to a full charge. The main drawback with both the Black+Decker trimmers is that they cannot handle heavier branches, so you need to trim your hedges regularly. That way you are only cutting light-weight material, which these trimmers handle well.

Stihl HSA 66

The Stihl brand pioneered battery trimmers, and while other brands might be catching up, they certainly remain on top of the game. Voted the Best Cordless Trimmer by consumer test sites, this machine has the power to cut through heavy material, and the balance to make that an easy job. Even with the smallest of its range of batteries, it will run almost 90 minutes, and with the strongest AR900 battery, it will last almost 8 hours. That option is probably only of interest to professionals, but the ability to choose the battery that suits you best is a big plus for this machine. Of course, there is a price to pay for the best, over $200 for the machine, plus up to the same again for the most powerful battery and charger. Still, if you want a machine that will handle the biggest overgrown hedge, this is the machine you want.

DEWALT 20-Volt 5.0Ah Battery MAX 22 in

If you don’t feel you need the full power of a Stihl machine, then this could be your best choice. Only $200 with the battery included, this machine will cut through ¾ inch branches, so if you haven’t trimmed your hedge for a while, you will be fine with this powerful machine. The battery will not give you anything like the time of the Stihl, but for most of us, that is not so important, as if we run out of power we can just come back the next day and finish up.


In the end, like so much in life, you get what you pay for. If your hedges are relatively small, the B+D options will probably work well for you. For larger, tougher hedges, the Dewalt or Stihl machines seem to be the way to go. Happy hedge trimming!

Grow Thuja Green Giant the Organic Way

A Fertilizer Program for Thuja Green Giant – Part 3

Feeding your Thuja Green Giant is the best way to get maximum healthy growth. Along with supplying sufficient water, this is the best approach to take, and gives you outstanding results. In this mini-series of blogs we have looked in some detail at plant nutrients, so that you can make informed choices when you come to choose fertilizers, and see past the advertising spin. As promised last time, in this piece we will look at how to grow your plants organically. Using natural fertilizers in the garden has gone from being a slightly-suspect fringe activity a few decades ago, to main-stream gardening today. More and more gardeners are choosing organic sources for plant nutrients, because they want to be ‘green’ and environmentally responsible. Like all newer things, there are some common misconceptions around this, which we will try to sort out here, and give some solid guidance for this ethical choice.

Plants Don’t Need Vitamins

No matter how you choose to supply them – from a bag of manufactured chemicals, or from the chemicals released by natural products, your plants use exactly the same handful of minerals we described in the earlier parts of this series. For the plant, these are exactly the same elements, and there is no evidence that plants can tell the difference between where they came from. After careful analysis, it is also clear that plants do not need vitamins or any other complex nutrients – just those basic elements.

That doesn’t mean that organic gardening and green growing are wrong. Not at all. Their emphasis is on the soil, not on the plant. What does that mean? Well, chemical fertilizers are designed and developed to deliver the chemicals needed by your Thuja Green Giant directly to the plant. They dissolve in the water in the soil, and are then absorbed through the roots, and sometimes through the foliage. Organic growing aims to build a healthy soil, with high levels of nutrients derived from the soil and the organic material added to it, so that your plants always have a good supply of exactly what they need. This more natural way of gardening focuses on keeping the soil healthy, and good plant growth follows – naturally.

Take Care of Your Soil

When we add organic material to our soil, we feed the natural cycles of decomposition and recycling that nourish all the plants growing in that soil. Organic material is the key to green growing, although we can sometimes use more concentrated natural materials such as sea-weed extracts, as boosters. Organic material is anything that was once alive, so all the parts of plants, plus animal waste. It can be garden compost you make yourself from garden trimmings, kitchen waste, egg shells, grass clippings, leaves, and even old wool or cotton clothing. There are lots of places you can find out how to make your own compost, and it is a wonderful way to start gardening organically.

If you live in a more rural area, you may have farms around you keeping cows, sheep, pigs or chickens. All these animals produce manure, which on most farms is mixed with straw and left to rot. If you can get some well-rotted manure, this is an excellent source of organic material for your garden. Never put fresh manure around your plants – it will burn them and can even kill them. Garden centers often sell rotted manures in bags, which is a very convenient way to use them, especially for a smaller garden.

When added to soil, this organic material continues to decompose, helped by the multitudes of fungi and ‘good’ bacteria present in healthy soil. This decomposition releases the nitrogen we talked about in earlier blogs, that builds healthy, green foliage and shoots on your plants. Nitrogen gives you maximum elongation of the stems, and your Thuja hedge builds height quickly. The decomposing organic material feeds the good microbes, which then more effectively release nutrients from the soil itself. It also retains moisture, helping your plants stay healthy.

As organic material decomposes, it turns into a substance called humus. This long-lasting material remains in the soil for years, holding nutrients as they are released from the soil minerals, and preventing them escaping in drainage water. The levels of good plant nutrients rise over the years – you get naturally healthier soil, and so healthier plants growing in it.

The Plants Will Take Care of Themselves

To effectively grow your Thuja Green Giant plants organically, you should start before you even plant them, adding organic material to the soil when you prepare the planting area. Dig or roto-till a layer 2 to 4 inches deep into the planting site, mixing it well with the soil. This will release lots of valuable nutrients – more than enough to grow your plants well without needing any added fertilizers.

To give young plants a boost, before they have spread their roots out into the surrounding soil to get to the nutrients from the organic material, you can use an organic supplement. One of the best is liquid seaweed. This is made from harvested kelp, which is a sustainable resource. Harvesting it doesn’t damage the environment, so you can use it while completely respecting the natural world around us. This liquid is diluted with water, and poured onto the roots of your plants, providing nutrients that are immediately available, and adding some longer-lasting ones to the soil as well. Once your plants are well-established, you don’t need to use it anymore, but keep some around, because diluted to a suitable strength it is a great food for everything from vegetables to flowers and even house plants.

To maintain good levels of organic material in your soil, and so feed your plants for maximum growth and health, you need to replace material that decomposes. Periodically, you should add new material as a mulch over the soil. You don’t need to dig it in, just spread it beneath your plants in a layer 2 to 4 inches thick. Cover the root area, extending out beyond the edges of your plants by as much as a foot. Not only will this material inhibit weed growth, and retain moisture, but organic mulch gradually breaks down, and works its way into the soil. On sandy soil and in high-rainfall areas, you may need to do this every year or two. On heavier soils, and in drier areas, every 4 or 5 years is probably enough.

By taking care of your soil, keeping it rich and healthy, and full of good microbes, your plants will benefit. You will be growing them in a natural, sustainable fashion, recycling household and garden waste through composting, and putting animal waste to good use, keeping it out of our rivers and lakes. This green approach to growing your Thuja Green Giant plants is certainly the natural way to go.

A Fertilizer Program for Thuja Green Giant – Part 2

A well-planned fertilizer program for your Thuja Green Giant hedge can make the difference between simply good growth, and spectacular, dense and healthy growth, giving you a solid hedge or screen several years earlier than it would otherwise happen. In this mini-series, we have been looking at fertilizers, not just saying ‘this one is good’, but giving the basics. If you understand plant nutrition, then selecting a fertilizer from the array available becomes a thought-out activity, not a hit-or-miss process. You can tailor your choice to what you know your hedge needs, depending on how it looks, and at what stage it is growing. You can make smart price choices, and understand the value of certain ingredients. As well, you have the pleasure of knowing more about your plants, and realizing that good gardening is something that can be learned, without the required ‘green thumb’.

In the first part of this series, posted last week, we looked at the ‘Big Three’, the major plant nutrients – Nitrogen, Phosphorus, and Potassium – that figure in the three numbers of the Fertilizer Ratio on every bag of fertilizer. We looked at what they do, and their roles in the good health of your plants. To summarize that, we can say the Nitrogen is the ‘growing’ nutrient, that causes shoots and leaves to develop; Phosphorus is the ‘rooting’ nutrient, that helps your plants develop strong, extensive root systems; and Potassium is the ‘protecting’ nutrient, that strengthens cells, and makes them more resistant to cold, insects and diseases.

Now let’s look at some of the important minor nutrients, which, like vitamins for us, are only needed in small quantities, but which are just as important as those Big Three.

The Minor Plant Nutrients

There are several nutrients that are used by plants in moderate quantities, although a lot less than N, P, K (these are the scientific symbols for the Big Three). These are Calcium, Magnesium, and Sulphur. Only in very acidic soils, with pH values below 5.5, can there be a lack of calcium and correcting that is not a matter of fertilizer, so we will put that one aside. Sulphur is present everywhere, and is almost never an issue for plants. That just leaves Magnesium.


We all know about the ‘wonder chemical’ called chlorophyll in plants that turns sunlight into sugar. It is what makes leaves green, and it is what feeds everything on the planet, directly or indirectly. Inside the heart of this big molecule is a single atom of magnesium. Without enough of that metal, no matter how fast the plant tries to grow, it will not be able to. Plants can rob older leaves to feed the more important younger ones if magnesium is in short supply, and Thuja will do that, leaving the older parts of the stems yellow instead of green, while the growing tips still look healthy.

This is not very common, mainly because most good fertilizers include magnesium in them. Look for the letters ‘Mg’ to find out if the fertilizer you are looking at has some, which will usually be listed as a percentage. It doesn’t have to be very much, and sometimes it isn’t even needed, but it’s good to see some in there.

The Micro-nutrients

These nutrients are also called ‘trace elements’, and both names tell us that they are only needed in minute quantities. These are sometimes called ‘vitamins for plants’, because they are just as important to plants as the big nutrients, but only tiny amounts are used. There are several, but only a couple are of importance. Iron, boron, manganese, zinc, copper, molybdenum, nickel and chlorine are the micro-nutrients that plants need, bringing the total needed to just 14 elements. Others are sometimes listed, but at this point those are not strictly essential, as they can be replaced with one or other of the 14. From a practical point of view most of this list can be ignored, since some, like chlorine, are so widespread that it is almost impossible to even demonstrate in hydroculture that they are essential. Nickel is needed only in very, very, minute quantities, and it need special equipment to even detect such small amounts. In most parts of the country, boron, manganese, zinc and copper are common in soil, and no supplements are needed. That just leaves iron, which we will look at in a moment.

Because it is hard to decide how much of these nutrients are needed, in modern fertilizers they are almost always simply included in small amounts. You will usually see them listed somewhere on the bag, given in ‘ppm’, which stands for ‘parts per million’. This is a commonly-used way of expressing very small amounts of something. Only the cheapest fertilizers will have no micro-nutrients, and the good news is that the materials in them will probably be a little impure, so they will be ‘contaminated’ with enough of these elements to provide your plants with what they might need.


This element is the only micro-nutrient that is regularly needed by plants as a supplement. We said that magnesium is in the chlorophyll molecule, well iron is in the enzymes that make chlorophyll, so no iron means no enzymes, which in turn means no chlorophyll. However the difference is very easy to see, because iron deficiency shows up on young, new shoots, which turn pale yellow. Like the other micro-nutrients, iron will often be in fertilizer you buy. Look for the letters ‘Fe’, which is the chemical symbol for iron. To get maximum growth from your Green Giant Hedge, iron is an important additive, since it will give your hedge that rich, lush green color that makes such a perfect backdrop for your garden. Nobody wants a pale hedge, and making sure you are adding iron will prevent that. This is by far the most common micro-nutrient deficiency seen, especially on soils that are alkaline, or if you have recently put down a lot of lime, hoping to improve your soil.

Enough for Now. . .

We seem to be on a roll here, so next week we will look at using organic fertilizers on your Thuja Green Giant hedge.