Monthly Archives: October 2018

Thuja Green Giant is deservedly popular. Fast-growing, drought and salt-spray resistant, generally avoided by deer and free of pests – what more can we ask of an evergreen? You may be planting a screen, or a more formal hedge, or using it as upright specimens around the garden. Whatever your need, its easy to see why this plant remains consistently popular across a large swathe of the country. Good results though, come from good beginnings, and with Thuja Green Giant – and of course with most plants – that good beginning is the planting procedure. If you are new to plants, or indeed if you have some experience but could always learn more, let’s look at the steps and stages of planting, so that your trees get off to the best possible start.

Ground Preparation

Even the best plant can only grow as well as the soil it is in. While it is probably possible in many gardens to just stick it in the ground and walk away, the best results – especially rapid growth and good establishment – depend on planting into prepared soil.

There is no particular secret to good soil preparation, and no matter what type of soil you have, the key steps are digging and enrichment. In a natural soil nutrients and finer particles are carried downwards by drainage water, so that the upper layers have fewer nutrients than lower down. Just as in farming, digging and turning the soil is a vital first step in improving the quality of your soil. For smaller areas, or just to plant one or two trees, hand digging with a spade will do a great job in a reasonable time.

For a larger area, renting or borrowing a roto-tiller will save a lot of work. Get the biggest machine you can handle, and that will fit into the area you are working with. The biggest issue with using roto-tillers is to get the necessary depth. The soil needs preparing up to 12 inches deep, or at least to the depth of a full-sized spade, and a roto-tiller can easily skip across the surface, making the area look great – until you discover that it has only gone down a couple of inches. The trick is to go over the area a couple of times at least, until it buries itself as deep into the ground as it can go. Then you know you have done the job.

Adding Organic Material

Find a source of rich organic material. This could be garden compost, rotted farm manure (cow, sheep or horse), spend compost from a mushroom farm, well-rotted leaves, or perhaps some other local alternative. Although peat moss has been widely used in the past, it isn’t really a top choice, and the environmental damage done by harvesting peat is another negative – but if it is all you can find, so be it.

After a quick first pass with the tiller, spread a layer at least 2 inches deep, up to 6 inches deep, and till it into the ground as you work the tiller deeper. The great thing about organic material is that it improves all kinds of soil. With sandy soil you will see an improvement in water retention and nutrients, while in a clay soil the same material increases drainage and allows more air into the earth, speeding up nutrient release. For a hedge, prepare an area about 3 feet wide, and a circle of similar diameter for an individual tree. It is better to create a continuous bed of prepared soil for a hedge or screen, rather than just make individual spots for each plant. In average garden soil you don’t need to add other nutrients, but in poor soil it pays to use a starter fertilizer as well, raked into the ground after tilling it.

Correct Spacing

When planting hedges and screens, the temptation is always to put the plants close together, to get instant coverage. This is a mistake, since crowded plants can’t develop properly, and will compete with each other. This easily results in some plants dying, and in all the plants growing tall but spindly. You won’t get the broad, dense hedge you are looking for, and the lower branches will soon die, leaving you with a collection of bare stems with leaves on the top. For Thuja Green Giant, allow at least 3 feet between each plant for a hedge, and up to 8 feet for a screen. This plant will become 12 feet wide in 10 or 15 years, so it will soon fill such relatively small spaces. By allowing enough space you keep the plants green and thick right to the ground, which is almost always what we want to see. Remember too to allow at least 3 feet back from a fence, wall or property line. You want to keep your trees on your side of that line, so they remain yours and don’t spread onto your neighbor’s land.

Correct Planting

When it comes to the actual planting procedure, remember to water the pots thoroughly the night before, and the ground too if it is dry. Never plant dry pots into dry soil. Dig holes into your prepared ground just a little wider than the pots, and the same depth. For a hedge, it is easier to get the spacing right if you take out a trench, rather than individual holes. That way you can line everything up, adjust the spacing to get it all even, and then plant – the result will be much better from the get-go.

Once you have the holes dug, slide the plants out of the plastic pots. To encourage the roots to spread outwards, and to prevent future problems with roots circling around and strangling the trunk, you need to open up the root ball. The simplest way is to take a sharp knife and make three or four long cuts, from top to bottom, one-inch deep down the sides. If most of the roots seem concentrated at the bottom, instead make a cross-cut on the bottom of the root-ball, again about one-inch deep. This might sound drastic, but your plants will thank you for it in the years to come.

Place the root-ball in the hole and adjust the depth so that the top is at the same level as it was in the pot. If your soil drains slowly, raise it up a couple of inches. In very poorly-draining soil, it is a good idea to build a low mound along the planting row, about 8 inches above the surrounding area, and plant onto that. This can really make a difference.

Once you have the trees in place, replace about two-thirds of the soil, and firm it down around the root-ball. Then fill each hole to the top with water and wait for it to drain away. This is far better than watering after you plant, as the water is down around the roots where you want it. Once the water has drained away, replace the rest of the soil and firm it gently. Remove any tags, string or stakes, and rake the soil level. If you are planting in spring or summer, putting a mulch over the roots is a good way to conserve moisture and encourage growth. You can use some of the same material you added to the soil. A layer 2 inches deep, kept a few inches away from the stems and off the foliage, will do the trick. Renew this every spring, or every second spring.

That’s it. You are done. Your plants of Thuja Green Giant are off to the perfect start. Now all you need to do is stand back and watch them grow.

Revolutions don’t happy often in the world of gardening, but back in the 1990s there was one – the arrival of Thuja Green Giant. The timing couldn’t have been better, because all across the country there were old hedges that needed replacing. Most of them were of an older fast-growing evergreen, Leyland Cypress, that had been very popular indeed following its introduction in the 1970s, as the hedging and screening plant everyone was planting. Those hedges were 30-years old or more, and many were beginning to suffer from disease, and becoming overgrown.

So when nurserymen saw Thuja Green Giant growing at the National Arboretum in Washington, DC, they were enthusiastic. The trees they saw had grown to 30 feet in about 30 years – much faster growth than any other evergreen, and they were impressive, dense, upright specimens about 12 feet across. No wonder those growers were impressed. They set to work propagating plants, and letting customers know that this plant was ideal to replace those old hedges, or for planting new ones.

Today, 20 years later, it is clear that their faith in this tree was not misplaced. It remains the number-one choice, and there are millions of satisfied gardeners all across the country who have used it to bring privacy and beauty to their gardens. So is this the tree for you? Here are some simple questions to ask yourself to find out.

How Big a Hedge do I Want?

All hedging plants are not equal in size – even if they look that way at the nursery. So the first thing is to calculate how tall a hedge you need. It always makes sense to go with the shortest possible one, to reduce clipping, especially to reduce the need to be up tall ladders and on scaffolding. Why grow a 15-foot hedge, when a 10-foot one would have done the trick? There are mathematical ways of calculating this, but the easiest way is to use a tall rod – some bamboo poles tied together for example, and with a helper holding it, see how tall a hedge you need to give you privacy or block that unsightly view. Hold up different heights until you can see coverage from the critical spots in your garden, or from those ground-floor windows. If it is upstairs windows you want privacy in, a hedge will rarely work, unless it is very tall, and therefore hard to manage.

If course, if you have plenty of room, you don’t need to clip, especially with a sturdy plant like Thuja Green Giant, and then the sky is the limit. Even then, consider shade. In winter a tall hedge can cast a 50-foot shadow, and that may not be what you want, so that is another reason why excess height is not desirable.

If you end up wanting a hedge less than 6 feet tall, then consider a smaller evergreen, like Emerald Green Arborvitae. This is also a to-choice if you live in zone 4 or cooler, as this native tree is extremely hardy, and grows well even up in Canada. If you live in zone 5 or warmer, and want a hedge taller than that, then Thuja Green Giant is your go-to plant. In very dry areas, if you don’t have much or any irrigation, then look to upright Junipers instead, as they are renowned for drought-resistance.

What is My Garden Like?

Thuja Green Giant is a tough plant, and it will grow almost anywhere. But it does have some needs, so check the parameters of the area you are planning to plant in. Is it sunny most of the time, or shady, perhaps beneath trees? For good growth with Thuja Green Giant, you want at least 6 hours of direct sunlight between spring and fall, and of course the more there is, the denser your plants will grow. If the area is beneath trees, then consider a more shade-tolerant hedge plant, like Yew, Holly, or, for smaller hedges, Boxwood.

The second consideration is the soil. Is the area always wet, even a week after rain? Wet, boggy conditions are not suitable, so again, another choice, is needed. The Dawn Redwood is the perfect evergreen for wet places, although it does become bare in winter. An alternative approach is to raise up the soil for your hedge into a low mound, at least 6 inches above the level of the surroundings, and 3 feet wide. As you throw up the soil, you also automatically create a drainage ditch around the mound, which will carry away the water that drains from the soil. Planted on a mound like this, Thuja Green Giant will thrive, using the wetter soil around it in dry periods.

The only consideration with your soil is its type. Is it sandy, loamy or clay? Although a lot is sometimes made of soil types, and certainly some plants prefer one or the other, Thuja Green Giant is not fussy, which is another reason for its wide-spread popularity. It will grow in most soils, and the good news is that by digging plenty of organic material into the ground before planting, you can improve any soil type. It improves sandy soil by retaining water, and it increases the drainage and air-penetration in clay soils too. A mulch over the roots – keep it away from the stems and off the foliage – will retain moisture in summer and keep your soil in better condition too, as it slowly rots down into the ground. In zone 5, mulch in spring, once the soil has warmed a little, but in warmer areas it can be done in fall or through winter. Most soils benefit from good soil preparation, which is much more useful in the garden than a ‘green thumb’.

Thuja Green Giant is Versatile

When you consider how adaptable this vigorous plant is, it’s no wonder it is the top-choice year after year. Although it has now been around for decades, there is no sign of it losing its place at the top of the popularity polls. So once you have checked your needs, the chances are good that this plant can satisfy them. With its rapid growth, it won’t be long before that hedge of your dreams is a reality.

While Thuja Green Giant is widely grown for hedges and screening, and justifiably so, given its rapid growth-rate and dense, upright structure, the use of this plant in gardens shouldn’t stop there. Fast-growing evergreens have a wealth of uses, so it’s time to take a closer look at what can be done with this versatile plant to solve a variety of garden design issues. Let’s get started.

Thuja Green Giant as Specimen Trees

There is something majestic and calming about a column of evergreen foliage. There is a range of plants that do this, but for many of them the wait is long until they become effective. Not with Thuja Green Giant. With proven growth of 3 feet a year in younger plants, it won’t be long at all until you have a bold green column making a statement in your garden. These fingers of green are ideal for adding a touch of geometry to your garden. Plant a pair on either side of your driveway, for example, or to flank a gate. Run an avenue beside a long driveway and bring a majestic feel to coming home. If you have a portico entrance, or large front doors, then it will look even more impressive framed by green columns on either side. Mark the corners of your patio with an upright exclamation point of green and add calming balance to your garden.

These upright features are important in any garden, formal or informal, because they create a sense of structure. It is easy to plant a lot of trees and shrubs on your property, but you don’t want them to become just a forest. Thoughtfully-placed accents show that this is a garden, not just a collection of plants. If you have a large lawn, you might have planted several trees on it. The natural tendency is to use shade or flowering trees, and that is the way to go, but adding some upright evergreens creates a fully picture, and makes the trees look even more impressive.

Another valuable place to put one or more specimens of Thuja Green Giant is in the corners of your property. These can be difficult spots to landscape well, but evergreens will create a more enclosed look that enhances the ‘garden’ feel. In small to medium-sized gardens, one will probably be enough in a corner, given that they will soon be 12 feet wide. But in larger gardens a group will most likely be needed.

Spacing Groups of Thuja Green Giant

The rule for grouping plants is simple, and is taken from Asian gardens, where even numbers other than two are considered unlucky, and everything is done in odd numbers. It might be more a case of ‘look’ than ‘luck’, but anyway, this rule is a good one. If you plant a group of more than one, even two is rarely right, but three just looks so much better. For larger areas – and Thuja Green Giant can quickly fill even a large dead spot, go to five or even seven plants.

The spacing between plants is critical to making groups work properly. The most common mistake is putting them too close. It just seems impossible that these compact little guys could even get so big they merge into a formless mass. They do – very quickly. While we exploit this for a hedge or screen, with groups of specimens we want an outcome that respects each plants individuality. You can reckon that in most gardens Thuja Green Giant will reach a spread of 12 feet. So plants spaced that far apart will take maybe twenty years to touch. When we stand back and look at a group of plants we see the upper part, and to create a group there has to be some unification. This means that 12-foot centers are going to be too far apart, at least for a very long time. 8 to 10 feet is usually the ideal spacing for this plant when forming a cluster. If you make groupings of more than three plants, plant one or two a little further apart – so in a group of five, three might be on 8-foot centers, and the remaining two on 10-foot. This might sound trifling, but it is on this attention to detail that distinctive gardens are created. If the plants begin to merge lower down, but remain as separate fingers up above, that is the ideal outcome. The goal is to look ‘natural’, so strict geometry is out – unless you are doing the Italian Renaissance in your garden.

For that avenue mentioned earlier, the spacing needs to be more, so that each tree stays as a distinct individual. 20-foot centers would be a minimum, which means six pairs along a 100-foot driveway. “Wait – that can’t be right!” did you just say? Yes, it is – you need a pair at each end, and four pairs to divide the 100 feet evenly into twenty-foot intervals. Draw a diagram if you don’t believe it.

Thuja Green Giant in Tubs

Although usually planted directly in the ground, Thuja Green Giant is in fact a plant that is perfect to fill big tubs with low-maintenance green. Not only do they grow fast, but they stay naturally tight, although there is nothing wrong with clipping to get a more formal, conical shape from your plants.

Since this is a large plant, bigger containers are needed. Half-barrels, or 24-inch planters, are the right size for trees that are going to be in those planters for a long time. Make sure they have large drainage holes, and try to source potting soil for outdoor planters, not houseplants. These soils contain composted bark or other coarser materials that don’t break down quickly, so the soil is more resistant to rain, and continues to drain well. A spring application of a slow-release fertilizer for evergreens is all it takes to keep your trees growing well. Thuja Green Giant is relatively drought resistant, so established plants in pots take a while to suffer if you don’t water, but it is best not to let that happen. Once the top few inches are dry, give them a deep soak until water flows from the drainage holes. Then leave them to become dryer again before re-watering. This is necessary to prevent root diseases.

These tubs can be placed on a terrace, around a pool, in the corners of a parking area, or just about anywhere you have paved surfaces. The benefit of evergreens is that they don’t start dropping leaves each fall, or flower petals either, so maintenance of the area is not impacted significantly.

However you use Thuja Green Giant around your garden, you will be amazed at the versatility and adaptability of this plant, and how easily it brings structure and form to any garden. Hedges are not the end of the uses for this plant – they are just the beginning.

Although in most areas fall is still in full swing, winter is indeed just around the corner. Some years it comes gradually, and other times it arrives out of nowhere. Which ever it is this year, now is the time to get ready for it. If you live in warm zones, that might mean very little, but in colder areas, where winter damage from cold, ice, snow or salt is common, some preparation now will make all the difference. You can avoid burnt foliage and broken branches with a few simple steps – done in fall.

Winter-proof Your Hedges

Trim in fall – a tight trim before the cold arrives will protect it from breakage
Apply fall fertilizers – choose a mix that is blended for fall application
Water well through the fall – even if rain has fallen, soaking the roots protects against winter burn
Protect against salt damage – burlap screens take some time and effort to erect, but they do the job better than anything else.

Trim in fall to protect your hedge in winter

The worst thing for a hedge is to go into the rigors of winter needing a hair-cut. An overgrown hedge will collect snow and ice, and branches will be caught by the wind more easily. The weight of that snow, and the twisting of the wind, caused broken branches and collapsed hedges. So get that trimming done well before winter comes, but after the growth has started to slow down. In cold areas that means late September or early October. In warmer areas any time in October is usually going to be suitable. The goal is to leave a few weeks for your hedge to harden after trimming, and perhaps produce a little fresh growth, and if you trim late that new growth will not have ripened enough to prevent it burning.

Hedging plants like Thuja Green Giant are very fast growing – the fastest evergreen around – so even if you trimmed in summer the chances are that there will be significant new growth on your hedge. Get out and give it a trim – you will really see the benefits next spring.

Two things to look out for. First, many people cut hedges by moving the trimmers upwards only, not downwards. This is a mistake, since it encourages long stems growing up the face of the hedge, and these are easily dislodged by wind and snow, leaving big empty spaces. Instead, always trim in all directions, so that the branches are more horizontal, with short ends branching out. This way, not only is the hedge structured in a more stable way, if a branch does die it leaves a smaller hole that fills in more quickly.

The second thing is the top. If you regularly have heavy snow, a rounded top will shed it better than a flat one – which admittedly does look more formal. If you do insist on a flat top, taper the sides in a bit more than normal, so that the top is as narrow as possible. Less snow will build up, and the chances of breakage are greatly reduced.

Put down a fall fertilizer

We usually think of fertilizer as something to put down in spring and summer, to stimulate lots of growth. Usually we don’t want growth in fall, as it will be soft and easily damaged by the cold. But there are other essential nutrients for plants – potassium in this case – which don’t stimulate growth, and instead increase cold resistance, and disease resistance too. Visit your local garden center and look for fertilizers labelled for fall, for evergreens. These have a lot of potassium, and not much nitrogen. Apply them straight after trimming, and they will toughen up your hedge to face the onslaught of winter.

Some of these fall fertilizers go even further. If you see a high nitrogen content on them, this is because the nitrogen is in a form that needs warm temperatures (over 40 degrees) to work. So they sit all winter, and kick in when spring arrives. This means no need to fertilize your hedges until early summer, so that is one job saved from what is a very busy season – a real bonus.

Keep up the water supply

Perhaps the single most important thing to do for your evergreens in fall is water them. This applies not just to hedges, and not just to newly-planted evergreen trees and shrubs, but to all of them, especially ones that you have seen burned in winter before. Often evergreens in foundation planting around the house have problems because the eaves reduce rainfall, and the ground is often dry.

Because these plants still have leaves, they lose water to the air all winter long. Cold winter air is very dry, and so they lose more than in summer. If the soil is dry they may not be able to keep up, and so the foliage dries out. There is a more subtle reason as well. If you live where the ground freezes hard, then plants can’t pull water from it easily – like trying to drink by sucking an ice-cube – but without a warm mouth. The more water in the soil, the less it freezes, and some water tends to stay in liquid form between the soil clumps. By soaking the ground a few times in fall – early on and then just as the ground is starting to freeze up, you make it easier for the plants to take up water, and so avoid winter burn, which is really a desiccation injury.

Protect your hedge from salt

Salt spray from roads and run-off from driveways causes a lot of damage to evergreens. Thuja Green Giant is one evergreen that has pretty good salt resistance, but others are not so good. The best way to protect from run-off is to stop using salt on your driveway. Switch to sand, which gives good traction without damaging your garden.

For highway salt, erect a burlap screen between the hedge and the road, higher than the hedge, to catch what drifts over the top. The secret is to put it a couple of feet in front of the hedge, with a space between, and NOT right on the hedge, as you see done so often in areas with deep winters. That way the burlap catches the salt, and stops it reaching the hedge. Letting the burlap touch of course simply holds the salt right on the foliage – worse than doing nothing at all. Screens also slow down the wind, and they protect from desiccation injury as well.

Sometimes things in the garden don’t work out as we thought they would. With hedges, that vision of a lush green wall framing our garden and bringing privacy doesn’t materialize – instead we have poor growth, gaps, thinning out, and other issues that arise. We want to fix them – and also understand where we went wrong. Some fixes are easy, others perhaps not, so this can also be a cautionary tale on how to avoid things going wrong.

‘My hedge looks pale and thin’

Instead of thick, bright-green foliage on your Thuja Green Giant, or other evergreens, they are growing slowly, and the leaves look pale, perhaps with some of the older pieces looking yellow. There are two possible reasons for this – lack of nutrients or lack of water – or both. Evergreens need plenty of nitrogen, and if your soil is sandy and lacking in organic material, then there will not be enough available. As well, if your plants have been dry for some time, perhaps due to drought, or because you haven’t watered them, they are not absorbing water. The pathway for nutrients is via water, so if there is very little water uptake, even if you have fertilized, and have rich soil, the minerals are not making their way into your plants – which are in survival mode, trying to cope with dryness by going dormant.

This one is an easy fix. First, establish a regular watering pattern. This will be a lot easier if you install a simple ‘leaky pipe’ trickle hose along the base of your hedge. Wind it in and out between the plants, so you cover the area well. Attach this to a regular hosepipe, and let it run for several hours, so that the water makes its way down to the roots. To restore your hedge, do this weekly for a couple of months, and then it will only be needed when the soil is dry. If this is a newly-planted hedge, then you should keep up the weekly watering into the fall on a weekly schedule. An easy way to do this chore automatically is to attach a timer to the outdoor faucet. These are inexpensive, and can be programmed to come on automatically, without the expensive of a full irrigation system.

If the problem is poor soil, then the best fix is to improve your soil when planting. Add plenty of rich organic material, like compost or rotted manures, when digging the area over before planting. If you didn’t do this, there is still hope. Start with concentrated fertilizer – it could be something organic like fish meal or fish emulsion, or alfalfa pellets, or a synthetic fertilizer. The quickest fix is with a liquid fertilizer – look for a high first number, perhaps around 20, in the fertilizer formula. This should be watered thoroughly into the ground over the root area, and you can also spray it at half-strength directly onto the foliage. Repeat 2 weeks later, and again a month later. You should see a big improvement. Once you have restored growth, start using fertilizer regularly, in spring and through the summer. Once your plants are healthy again you can switch to a granular fertilizer, which is much easier to apply. There are also slow-release formulations that only need one application a year – an even bigger time saver.

‘The bottom part of my hedge is looking thin’

Once a hedge has grown to its full size, the lower parts can weaken and thin out. In extreme cases the whole bottom section for several feet may die, leaving your hedge on bare trunks. Yet that lower part is usually where we want it to be thick and green. What to do?

This problem is most often seen on the north-facing side of a hedge, and there are two possible causes. It might be you have planted shrubs in front, and as they grow they are making a lot of shade on the bottom of your hedge. That shade will reduce growth, and it may kill the lower branches. Evergreens like Thuja Green Giant need sun or bright light, and in the shade of shrubs, especially other evergreens, they will abandon their lower branches, and put their energy into the upper growth – which is not what we want in a hedge. The fix for this is simple – trim those plants in front, if necessary removing some – you can transplant them somewhere else in your garden – to let the light in. it is best to leave a pathway at least 3 feet wide between the outer branches of other plants and a hedge.

The second reason could be poor trimming, specifically, letting the top growth become too wide. Look at your hedge from the end. Is the top wider than the bottom? If it is, then the upper part will draw all the energy, leaving the lower branches to starve and weaken. If you catch this problem while the lower parts are still reasonably healthy you can turn it around. Start trimming more from the top, in stages, until you have a slight inward slope on the face of your hedge. Remember that you can’t trim evergreens back to bare branches and expect then to re-shoot. With a few exceptions, like yew trees, they won’t. So you need to cut back in stages, always leaving some green. If the problem is not too extreme you will be able to reverse this error. Of course if you are starting a new hedge, don’t let it happen in the first place, and always lean the face of the hedge backwards a little, to let light to the bottom, and inhibit the upper growth from taking over.

Sadly, once that lower part is dead, you won’t be able to bring it back. Planting small plants along the bottom sometimes works, but it often doesn’t. It is almost always better in the long run to start again with a new hedge.

‘Every spring my hedge is brown’

There are three reasons this might happen. The first and most obvious is that you have chosen plants not hardy enough for your location. Thuja Green Giant is hardy to zone 5, but not colder. Other evergreens will take colder conditions, while others need more warmth. Always match your choice of plants to your location.

The second possible reason is salt damage. If your hedge is along a roadway that is salted, then drifting salt can burn the foliage. Thuja Green Giant is tolerant of some salt spray, but other evergreens for hedges are not. The best solution, if this is a regular problem, is to erect a burlap screen a couple of feet in front of your hedge, to catch the spray. Don’t let it touch the hedge, otherwise the salt will just sit there, and the damage can be worse.

The third reason is lack of moisture at the roots. If neither of those first two reasons seems to be the problem, then soak your hedge well shortly before the soil begins to freeze up. Apply a mulch over the roots as well. This will keep the ground from freezing so hard, and your hedge plants will not desiccate in the cold, dry, winter winds.