Monthly Archives: September 2017

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.

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.

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.

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.