As record cold sweeps much of the country, and white-out storms engulf highways, towns and of course our gardens too, there will be many people, when warmer weather returns, looking at collapsed hedges, broken branches, and seeing years of growth destroyed in a matter of hours. Hedges are vital components of many garden landscapes, bringing privacy, reduced noise, extra warmth and creating a calm neutral garden backdrop. When damaged all that is destroyed, and there is no such thing as ‘instant hedge’ to replace it with. Could the damage have been prevented? Can I repair it now? Do I need to plant a new hedge? These are the questions that will be going through everyone’s head as they survey the situation in their garden.

Has the cold killed my hedge?

Consider this – current record-breaking low temperatures are bringing lows from much colder zones than your own ‘normal’ one. If the difference is slight, you will probably only see browning and scorching of foliage. If it is significant, then you could easily see a lot of dead plants, including hedging evergreens, when spring arrives. Since this deep freeze has lasted several days, the low temperatures have had time to ‘bite’ into your plants. While smaller plants below the snow will probably be fine, shrubs, trees and hedges could easily be damaged. If you know what plants your hedge is made off, here are the minimums usually recommended for some of the most common ones, in the Fahrenheit system normally used in America. If your neighborhood experienced temperatures more than 10 degrees below these, then there is a very good chance you will need to replace your hedge come spring – sorry.

• Emerald Green Arborvitae – minus 50 degrees
• Thuja Green Giant – minus 20 degrees
• Leyland Cypress – minus 20 degrees
• Italian Cypress – 0 degrees

If you are replacing a hedge, the question becomes, ‘should I use a hardier plant this time around?’ In the past we would have said, ‘no’, because in most areas a low temperature significantly outside your zone only happens about every 40 years – otherwise you would be in a lower zone, right? But with an increase in extreme weather, probably due to man-made global warming, these events could become more common, as the climate shifts to a new normal. So if you are already at the bottom of the hardiness range for a plant, moving to something a zone or two hardier could be a good idea.

What now? Can I cut it back and re-grow it?

This is a common question when hedges are broken, and if only we could say, “yes”. That of course depends on what plant has been used to make it. Hedges of broad-leaf evergreens, like holly, can be cut back as much as you need, and they will quickly re-sprout, so no problem at all. But most people prefer the smooth surface and easy trimming of conifers – the needle evergreens, especially Arborvitae, Cypress, and of course Thuja Green Giant. These plants cannot re-sprout from older, bare branches – which is why it is best to trim regularly, starting right after planting, and trim little and often. There are just a few evergreens of this type, with yew trees being the most well-known and widely used for hedges, that will re-sprout from older branches. They can be cut right back to a few limbs, and they will quickly regenerate. For the rest the answer is, “No”.

This means that when you are cleaning up your damaged hedge, cut branches back to a side-branch with foliage on it – otherwise you will be looking at that bare stump for a very long time. Even if the result is a very ‘gappy’ hedge, with care, fertilizer and regular trimming, a lot of it may fill in again. Give it a couple of years, and then re-assess.

Can I fill in gaps with young plants?

This is a possible solution when only part of a hedge is damaged, but it can fail, mainly because it is hard for new plants to become established in soil full of the roots of the older plants. There are three things you can do to improve your chances. First, use the biggest plants you can handle. These will have a large root-ball and be able to cope better with the surrounding trees. Secondly, prepare as big a planting hole as possible, removing old roots, and making a good-sized gap for the new plant. You can also put a root barrier on both sides – not all around – to slow the invasion of that nice fresh soil by the older plants in your hedge. Landscape fabric, or barriers for bamboo, are usually available at local garden centers. Finally, be sure to water and fertilize the new plants regularly and thoroughly, for the first two growing seasons, to give them a chance to compete.

Remember when planting to put the stem of the new plant in line with the existing ones, and not, as some people do, with it in front, level with the existing hedge front. If you do that, the new plants will not be able to develop properly, as they will be over-trimmed on one side.

Should I just replant?

In the end, this is often the best advice. Fixing damaged hedges is difficult, unless the damage is minor, and removing the old one and replanting can be easier. It will also liberate a large area of your garden, as old, over-grown hedges – the type most likely to collapse in a snow-storm – are often very wide and steal lots of your garden. Of course, a new hedge will take time to grow, but if you choose fast growing trees like Thuja Green Giant, then the time will soon pass, as with growth-rates of 3 to 5 feet when young – really, this has been demonstrated in trials – you will be looking at a great hedge in just a few years. Remember this time to keep it well-trimmed, and narrow, especially at the top, as wide tops and overgrown hedges are the ones that usually fail.

In recent years there has been a quiet revolution in hedge trimming. Not in the way it is done, but in what tools are used to do it. Commercial landscapers and other gardening professionals were the first to embrace this change, but gardeners are now starting to get on board too, and they are discovering that it is possible to both throw away that noisy, smelly, gasoline-driven trimmer, and forget about that awkward and dangerous trailing cable too. The battery revolution that gave us the cordless phone, then the cordless vacuum cleaner, and dozens of other cordless appliances, has now given us the cordless hedge trimmer – bringing a freedom to trimming that has to be experienced to be believed.

Cordless trimmers have two major advantages over the older choices. First, they are as quiet as any electric trimmer – it is really just the cutting action itself that makes noise, since the electric motor is basically silent – but that trailing cord, and yards and yards of extension are gone. Until you try one it is hard to realize the freedom you have, but trimming suddenly became a whole lot more pleasant. Plus, the elimination of the gasoline engine means not just quiet, but a total lack of fumes, and no gas-cans in the garage either. We are all much more aware of air pollution than we used to be and removing that smelly – and often smoky – machine from your yard is wonderful. Now you can smell the fresh-cut cedar instead of gas fumes.

Like all those other cordless appliances, these newer trimmers are powered by the battery revolution that created the re-chargeable lithium battery. Like all batteries, they can run out of power, and although re-charge times have been reduced hugely, getting the job done can fall apart when the battery runs flat. Make sure the machine you are considering has a lithium battery, and not a cheaper (and inferior) nickel-cadmium one. Lithium charges quicker, and holds far more power, and that is a key consideration. Recent developments have greatly reduced the charging time, with some higher-quality trimmers completely recharging in the time it takes you to make and drink a cup of coffee or eat a quick lunch. That saves you the cost of buying a second battery. Look at the voltage too, a 20-volt battery is minimal, and for more power, and therefore more speed and endurance, consider a 40-volt battery,

How Much Trimming Do I Need to Do?

This is the first question to ask yourself. If you have one large hedge, then how long do you currently take to trim it? If you have planted a new hedge – maybe with Thuja Green Giant – then you might not have much idea, and it depends very much on how tall your hedges are. Also, there is a limit to how long you can work trimming without a break. However a hedge trimmer that runs out of power in less than an hour is only going to be useful for small shrubs around the house, or a short section of boxwood.

Tests of cordless trimmers show that between one and two hours is normal, despite what manufacturers may claim. If you choose a smaller machine, then consider getting a second battery, which will avoid the problem of suddenly running out of power just when you are almost done. Even if you don’t think you will need a second battery, check if you can buy one, as some trimmers don’t offer that, and if the battery fails you will be looking at buying a whole new trimmer.

How Long Do I Need to Spend Trimming?

As a home gardener you probably won’t need more than a couple of hours, and remember too that there is only so long you can hold a 10-pound machine in the air. Most better-quality cordless trimmers will last between one and two hours before needing charging, which will probably be sufficient for a session – keep it turned off when you are moving around, putting up or taking down ladders, etc., and only run it while you are actually trimming. If you want more time, or those commercial landscapers reading, there are two options that will help you keep going longer. Move to a backpack battery – which is also a good option if you find the weight of a trimmer with its battery a bit much – as these have much longer run-times, or secondly, invest in a STIHL trimmer. This company pioneered battery-powered garden equipment, and their tools have outstanding battery life – the AP300 36-volt battery is good for about 5 hours of steady running.

How Often Do I Trim?

This might seem like an odd question, but it relates to a major limitation with trimmers, which is the thickness of branches they will cut through. If you don’t trim often, or just have an informal screen you cut back every couple of years, then you will need a trimmer that can cut through ¾-inch material. There are two things to look at here. Look at the absolute width of the guide spaces – obviously you can only cut what will fit into the guide – and secondly, how quickly will it cut through that branch. There is a surprising degree of variation in this test, but generally a more powerful machine will obviously cut faster. If you trim infrequently, then you should consider a more powerful machine, and avoid the frustration of jamming branches, or resorting to loppers to get the job done. If you are a frequent trimmer, then you will be cutting thinner and softer material, so this issue is going to be less important to you.

How Tall and Wide is My Hedge?

When putting in a hedge, and deciding on its height, always go for the minimum. It becomes exponentially more difficult to cut hedges as they increase in height and being able to trim from the ground is so much faster than using ladders. The length of the cutting bar, and the availability of extension pieces, are big factors to consider if you have taller hedges. Some extensions can cut at 90^o, which means you can trim the top from the ground. Cutting bars vary in length, and between 16 and 20 inches is a good all-round length to go for. Shorter blades are perfect for smaller bushes, and longer ones – they go up to 40 inches – are a good choice if you have a large hedge.

What is My Budget?

Obviously this is important to us all. Expect to pay about $100 for a basic, lower-power trimmer, and over $200 for something more durable and substantial. Commercial-grade equipment will run much higher, but using it is over-kill for most home gardeners.

Winter is a difficult time in the garden, especially if you live in colder regions, although even in warmer areas sudden cold snaps can wreak havoc, as happened in the South recently. Snow, cold winds, and in warmer areas periods of dryness, can all damage hedges and destroy the careful work and nurturing of years. So taking preventative steps is always a worthwhile investment of time, and with just a little effort and attention we can make the difference between a hedge that comes through winter looking perfect, and one that needs lots of attention and time to come back again.

Tips for Winter Care of Hedges and Evergreens

• Keep the soil moist, by watering through fall, and during winter dry spells
• Protect the foliage, especially with new hedges, by using an anti-desiccant spray
• Keep salt at bay, with screening placed away from the hedge, not right on it
• Use a high-potash fertilizer, this element protects from dryness by thickening the cell walls

Water Your Hedge in Winter

In every region, watering is the single best thing you can do for your hedge. In cold areas, where the ground freezes for periods of time, and even all winter long, evergreen plants find it difficult to draw up water from the frozen ground – imagine drinking a glass of frozen water. This means that the foliage, which is still losing water to the atmosphere, especially when dry or cold winds blow, can desiccate and become dried out. This may not be noticeable until spring, when new growth should begin, and instead the warmer days complete the drying process of these already-dead branches. This effect, called ‘winter burn’, is seen not only on hedges but on other evergreens as well, so while watering your hedge, water your specimen evergreens too.

Watering helps because if the ground is very moist it takes more cold input to freeze it, and some un-frozen water will remain available to your trees. Since the foliage will survive best if it is fully plumped-up with water when the ground freezes, you should begin this winter watering in late fall, and continue until the ground freezes. Especially with younger, newer hedges and evergreens, mulch over the soil will also help, not just to conserve the moisture you have added, but to keep the soil warmer and reduce the intensity of freezing.

In warmer areas watering issues can also arise, as long dry stretches are common in winter, and just because the temperatures are lower doesn’t mean the ground is not drying out. It is easy to be caught unawares when cold sunny days draw lots of moisture from evergreen foliage, and directly from the ground. Check around the base of your hedges and evergreens weekly, and if the soil seems dry, give it all a good soaking.

Speaking of soaking, it is also important to water correctly. Standing for a few minutes with a hose spraying is unlikely to be very effective, since you want the water to penetrate deeply into the soil, not just dampen the surface. A slow-running hose pipe, or a soaker hose of some type, will be far more effective in re-filling the deeper water reservoirs in your soil. When putting in a hedge it makes lots of sense to install a simple watering system at the same time, which can even be connected to a timer. You don’t need a full-scale irrigation system – just a trickle hose or ‘leaky pipe’

In colder areas you probably won’t need to water during winter, but watch out when early spring arrives, as then too the soil can dry rapidly as the temperatures rise, especially if it has been a dry winter. Remember to keep checking until your full spring and summer schedule becomes established.

Use Anti-Desiccant Sprays

It is surprising that these sprays, used by professionals for decades, are not used much more by gardeners. Perhaps it is the distrust of spraying, but in fact these materials are all-natural, and so they are completely safe to use. They contain an ingredient called ‘pinene’, which is extracted from pine trees cut for lumber. When mixed with water this material forms a giant network of molecules that becomes a water-proof film across the foliage it is sprayed on. It is this coating that greatly reduces water loss from the foliage, and that makes it so useful. On evergreens in winter, especially if you have planted them recently, it can make an enormous difference, keeping them green and healthy even in difficult and exposed locations. Spray shortly before the ground freezes, and if there are periods above freezing during the winter, especially if it rains, then try to get out and re-spray, as heavy rain will weaken or remove the coating. It is basically invisible once applied, so it is much more attractive, and more effective too, than the old-fashioned burlap wrapping still seen in some colder areas.

Protect your plants from salt spray and runoff

Salt is the enemy of plants. It sucks moisture out of the foliage, and out of the roots too if it enters the soil. Luckily its use is declining, and there are better alternatives for your driveway, especially if you have a hedge alongside it. You can’t control what your city puts down though, so if you have hedges along the roadside, you can easily have them severely damaged by salt drift blown up by traffic or high winds. The best protection is to catch it before it lands on your plants, and the simplest method is to put up a burlap screen, placed a foot or so in front of the hedge, and a little taller. This will trap the salty spray and hold it away from the foliage. A common mistake is to hang the burlap right on the hedge, but if you think about it for a moment, by doing that you are holding a wet, salty cloth against the leaves, which is at least as damaging as doing nothing at all. That gap is important, so make sure you create it when putting up your screening.

Use High-potash Fertilizer in Fall

You won’t see it labelled with that name, but if you read the label you will see a relatively high number at the end of that formula of three numbers showing the composition. These fertilizers are often sold as ‘fall-fertilizer’ for evergreens, and their secret ingredient is the element potassium, often called potash. This is held in the plant sap and causes the cells to take up extra water. Not only does this protect against drying out, it stimulates the cell walls to thicken, so that water is lost more slowly through them. As well, the extra elements in the sap makes it less likely to freeze. Together, all these effects reduce the risk of winter damage to the foliage. Although not really a winter tip, as it should have been done already, it is something to think about for next fall, to give your evergreens the protection they need.

The holiday shopping season has arrived, with Black Friday to kick it off. Lots of bargains around, and a great time to buy gifts for family members. If you have a garden, chances are you have a hedge – Thuja Green Giant perhaps, or some other evergreen. If you do, then it is almost certain that the person in your household who takes care of that hedge – trimming, feeding, watering during dry periods – would love something to make those chores go faster, and be done better. Are they battling with old trimmers, perhaps trailing an electric cord with multiple duct-tape repairs? Or still using that rickety old ladder? Shame! Start browsing the bargains to find some new, modern tools and equipment to help them do a better job more easily. If you are reading this, and you are that person, then give yourself a treat – you deserve it.

5 Black Friday Bargains for Your Hedge

• Cordless Trimmers – no more trailing cords, or noisy gas engines, with the new generation of rechargeable batteries
• Pruning Ladders – a three-legged ladder is a revelation for hedge trimming
• Hand Pruners – useful for thicker branches, and a million jobs around the garden
• A Load of Organic Mulch – perfect for conserving moisture and feeding your hedge (and the rest of your garden too)
• Trade in your old hedge for a new one – Thuja Green Giant remains the number one top seller

Buy a Cordless Trimmer

If you are tired of trailing yards of electric cord around your yard, or trimming a hedge surrounded by gasoline fumes and noise from an engine, then there is good news for you. Advances in battery technology mean that light-weight rechargeable lithium batteries are now perfect for hedge trimmers. If you don’t believe it, look at the professionals in your area trimming and hedges, and the chances are you will see them with battery trimmers. If it’s good enough for them, what are you waiting for? Look for Black Friday bargains in the trimmer department and go for real portability without heavy equipment. Smaller trimmers have the battery build into them, but if you have a lot of hedges to trim, consider a backpack battery. It will give you all the hours you need to get the job done, and it makes the weight totally manageable. Consider too that many battery trimmers are part of systems that include blowers, edgers, and other tools, all interchangeable. You can do all your garden chores quickly and efficiently with a single battery system.

We reviewed cordless trimmers recently, so take a look for more details. Once you switch you will never look back.

Climb the Ladder of the Professionals

The great secret of hedge trimming is the existence of three-legged ladders. Even many pros don’t use them, but these amazing ladders are certainly used by the best gardeners, not just to trim their Thuja Green Giant hedge, but for trimming all there smaller trees, clipped specimens, and for picking fruit too. If you have anything bigger than the smallest garden, these ladders are a necessity. Instead of a pair of legs at the back there is just one. The front steps usually flare out at the bottom for extra stability. That single leg can easily be slipped inside a hedge, letting you climb up and be close to the face. This is especially useful for trimming the top, where it makes it so much easier, especially if you don’t have really long trimmers.

More correctly called ‘tripod ladders’ or ‘orchard ladders’, these are available from several suppliers across the country. It is also much easier to put up a tripod ladder than a regular step ladder, because they are so much easier to make stable on uneven ground, or on slopes. Save your step ladder for indoors, or on flat terraces, and use a tripod ladder around the garden. We looked in more detail at these in a recent blog. Take a look and make the change – you won’t regret it for a moment. Indeed, you will wonder how you ever got by without one.

Hand Pruners – a simple but vital tool

Every gardener needs a good pair of pruners. Tucked into a back pocket, or in a sheath on your belt, you will always be pulling them out for that broken branch you come across, or for big pruning jobs. When trimming a hedge they are helpful for any thicker branches, or to tidy broken pieces, or to catch stray bits. Since you will be using them regularly, avoid bargains, and track down something worthwhile. Always use the type called ‘by-pass’ pruners. These have a single sharp curved blade that slides by a blunt, solid blade. Other kinds with a flat-edged blade landing on a flat second blade work fine when brand new, but the slightest chip or dent and they will tear the bark, instead of making a clean cut.

The classic gardener’s brand is Felco – made in Switzerland for pruning grape vines, but now the grand cru of pruners for gardens too. Perhaps a Black Friday bargain to be found, but worth every dollar, whatever you have to pay. Blades and other parts are easily replaced, so they last for decades, even with constant use.

Mulch – the garden Miracle Food

Honestly, we don’t know if mulch suppliers have Black Friday bargains, but hey, they are probably open to negotiation. In any case, a load of bulk mulch is the perfect gift for any hedge grower, or any gardener. Call local topsoil suppliers, who will usually have a supply of rich, organic mulch – from a local mushroom farm, dairy or stables most likely. If not, they may have municipal compost, or composted bark as a last, but still worthwhile, resort.

Mulch over the roots of your hedge – keep it a few inches away from the stems, and off the foliage – will conserve moisture during summer and keep the roots cool. It will also slowly break down into the ground, adding nutrients and materials that bind together the soil particles, improving drainage and air penetration into the soil. All these things are guaranteed to improve your soil, and so improve your plants, no matter what kind of soil you grow on. Use mulch all over your garden. If you are not already a convert, you soon will be!

Replace your old hedge with Thuja Green Giant

Don’t forget that plant suppliers have Black Friday too, and you can bet there are special offers on the number-one selling hedging plant, Thuja Green Giant. Renowned for its fast growth – three feet a year or more when young – and its resistance to deer, salt-spray, and drought, you can’t go wrong anywhere from zone 5 to zone 9 with it.  Allow 3 to 5 feet apart, depending on how quickly you need it to fill in. Measure what you need, and order now while the bargains last.

As the first snow begins to fall in the north, it is time to prepare your evergreens for winter, so they emerge in spring fresh and healthy, not dry and sad. It just takes a few simple steps, but the difference can be enormous.

5 Simple Steps to Help Evergreens Survive Winter

• Water them deeply and well – the first and most important step
• Mulch the root zone – it reduces soil freezing, and keeps the soil moist too
• Spray with anti-desiccant – these sprays create a water-proof barrier to evaporation
• Consider netting – it prevents breakage, reduces wind damage, and beats burlap hands-down
• Feed with potash – it toughens the leaves against the cold

What’s the Problem?

Even the toughest evergreens – especially in their early years – benefit from some attention in late fall. Most gardeners have experienced a spring when some of their evergreens came out of winter brown and crisp. They might have re-grown, but they rarely recover completely, and if it is a hedge, the result can be devastating.

The clue to the problem lies in the name – ‘evergreen’ – because it’s the way these trees keep their leaves all winter that causes the problem. It’s not that the leaves aren’t hardy enough to survive the cold. No, the problem is water. When the soil freezes it becomes much harder for these trees to draw up the water they need to keep their leaves moist. The low humidity and cold winds of winter cause water to be lost from the leaves, even though these plants have tough, waxy coatings on those leaves. If the lost water cannot be replaced, the leaves slowly dry out, and die. They may not change color until spring, looking green as winter ends, but the damage has been done.

Water your evergreens

The first and most important solution is watering – late, just before the ground freezes. No matter how wet fall has been, beneath the foliage, and especially where trees around your home are protected by the eaves, the soil can be dry. The more water in the soil, the less likely it is that all of it will freeze. If there is some free water left, your trees can much more easily replace what they lose from their leaves. Winter burn, as that dead foliage is called, will be prevented. This is especially important when trees are young, because the roots will not have spread far, or very deep, so they are dependent on a small volume of soil for their water needs.

So leave a hose running slowly for a few hours near the base of each tree, or if you have a hedge put down a ‘leaky pipe’ hose and soak the whole length. Slow soaking is much better than using a sprinkler, or hand watering, because the water goes deep, and the soil will be completely wetted, not just moist on the top.

Mulch the root-zone

Once the soil is wet, let’s keep it that way. A couple of inches of mulch – perhaps shredded bark, or even chopped leaves from your trees – will reduce evaporation and keep the soil damp. Put it down within a few days of that soaking, keeping it off the foliage, and a few inches from the trunk. Cover a wide area, so that all the root zone is protected. There is a less obvious value to this too. By insulating the soil surface you trap the existing warmth in the soil, and reduce both the time it stays frozen, and how deep it goes. In a mild winter you may prevent freezing altogether, which is an ideal outcome. That mulch can be left in place to conserve moisture next year too, and just topped-up each fall. If you use something rich, like compost, it will also feed your trees, and improve the properties of the soil over time.

Spray with anti-desiccant

It is amazing how few gardeners use a product that professionals in cold areas use extensively. Anti-desiccant sprays create a thin, invisible plastic film over the foliage, which reduces water-loss dramatically. They are widely used by landscapers after planting all sorts of trees, as well as for winter protection. Pick some up at your garden center, and spray while the temperatures are above freezing, but as close as you can to that first hard freeze or snow fall. Once dry – which takes just a few hours – they resist rain, but they can in time wash off. If you have a lot of winter rain, and there is a warmer period at some point in the winter, then spray again if you can. If you are not familiar with anti-desiccants, give them a try. You will be amazed at the protection these products give, on both conifers and broad-leaf evergreens like Rhododendrons, Holly, and Cherry Laurel.

Consider netting

In cold areas there is a long tradition of wrapping evergreens in burlap for the winter, but there is a much better alternative available, in the shape of netting. Black or dark -green, with ½ inch squares, it is invisible from a few yards away. It doesn’t destroy the look of your yard, but it keeps the branches together, and stops them breaking under the weight of snow or ice. Surprisingly, it also reduces desiccation injury, because by holding the branches more tightly together it slows down the passage of the wind through the branches – a double benefit. In spring there is no rush to remove it, while burlap can cause fatal heating-up and premature sprouting, both of which are damaging. Just try and remove the netting before new growth begins, otherwise it can become tangled, and harder to remove safely.

Feed with potash

Potash, the element potassium, is known to improve winter survival, and bring evergreens through the winter in good shape. Starting as early as October, feeding your evergreens with a fertilizer high in potash (the last number in the fertilizer formula), but low in nitrogen (the first number in the formula), will help the foliage hold moisture, and thicken the walls of the cells against cold damage. You should be able to find these fertilizers labelled for hedges and evergreens in fall, and they do a great job of giving an extra level of protection.

 

You may not need to do all these things, depending on your plants, and where you live. But they are all great ways of protecting your evergreens from the ravages of winter – a little care goes a long way.

Hedges – especially evergreen ones – are a vital structural part of many gardens. They define the boundary of our space, marking property lines and giving screening from the street, neighbors, and open spaces. Besides the practical benefit of screening, in terms of warmer gardens with less wind, there is value in the sense of enclosure they bring, and the definition they give to the space.

All these things motivate us to put in hedges, but while our intentions and dreams may be good, things don’t always work out the way we thought they would. As you look at your garden, taking stock and wondering if you should make changes, do you look away when your eyes reach the hedges? Are you embarrassed by them? Do they annoy you, thinking of the investment that didn’t pan out, and instead left you with something unsightly?

There are several common faults seen in hedges, and if you have them perhaps something can be done to save the day and turn that unsightly hedge into something attractive. Or maybe not. . . Deciding if your hedge can be saved, or if you should replace it, is the subject of this blog, and we will look at the different things you might see, their causes (so you don’t repeat your mistakes), and what, if anything, can be done. This will give you valuable insights in guiding you to the best next step.

Common Hedge Faults

There are several ‘symptoms’ of bad hedges, so let’s start with diagnosis:

• Doesn’t reach the ground – this is usually because the lower branches have died, since most hedging plants are green to the ground when they are new. Over time the lowest branches first stop growing, and then die. You may have had to cut them off, and perhaps you hoped the trunks would sprout again, but of course they didn’t.
• The lowest parts are thin and sparse – this is the precursor to the first problem and connected to it. Once you start to see little growth down below, which is easy to notice when you are trimming, and don’t need to trim the bottom 3 or 4 feet, then you are heading into a future with a hedge that is bare at the bottom, letting wind, animals and children wander through, and defeating he purpose of your hedge.
• The top is overhanging – as you walk by your hedge, you (or passers-by) collide with the upper parts, because it leans outwards. Besides the nuisance issue, if you live where there is significant snowfall, a broad top is much more likely to collapse under the accumulated weight of snow and destroy the hedge completely.
• There are gaps where branches or plants have died – this can leave ugly spaces, and really make a hedge look bad. This might be caused by disease, and its tempting to blame such outside forces, but in reality plants often die from overcrowding, and if a branch dies and leaves a big hole, there is something wrong with your trimming technique.

Why is this happening to me?

How do these faults come about, and how, with my spanking-new hedge, can I prevent them from happening again? These symptoms can be traced back to two issues – poor planting and poor trimming. Let’s look at each one.

Spacing

Putting your plants in the ground so you get a reasonable screen quickly, but don’t overcrowd them, is vital to a healthy, working hedge. There is a great temptation to plant those nice young plants almost touching, so that they will become a solid wall almost immediately. Tempting as this is, it is a big mistake. By planting closely together you increase competition between the young plants. They struggle to grow upwards, seeking the light, and two things can happen. First, the lower branches never develop properly, and soon die, leaving the bottom area bare. Secondly, slightly weaker plants become weaker and weaker, until they die, leaving a gap in what is by this point a substantial hedge. You can see how initial spacing errors relate to hedges that are thin or open at the base, and also to hedges that develop gaps.

Correct spacing varies, depending on which species of hedging plant you use. For larger plants like Thuja Green Giant, three feet or more is a good starting point. In theory, with a 12-foot spread, they could go 10 feet apart and still make a solid wall, but that would take time, and they would have to be allowed to grow fat too, creating a hedge that takes up too much room. So 3 or 4 feet is about right, although if you plant a staggered double row (a good idea by the way) then 5 or 6 feet apart in the rows would be spot-on.

Trimming

Most other problems come from trimming incorrectly, especially allowing the top to become wider than the bottom. It takes discipline to prevent this, as it is natural for a plant to spread outwards as it grows up. You should always be taking more from the top, trying to keep it as thin as possible, when you trim. If you just take the same amount off all over, a wide-top hedge is the result. Keeping the top thin prevents obstruction, allows more light to reach the bottom, and that narrow top is much better at shedding snow and not accumulating so much that it breaks open.

The second issue is trimming upwards only. You should trim in all directions, so that the branches have short, tufted ends, not long strands growing up. If a branch dies – and they do, even on the healthiest hedge – then it only leaves a small hole if you have horizontal branching. That quickly fills in and doesn’t leave the 6-foot gap a long, upward-growing branch will leave. Again, you can see how these errors create the symptoms we began with.

Can I Fix It?

So how many of these problems can be fixed?  A lot depends on the age of your hedge, and how advanced the problem is. If you are just seeing the lower part thinning out, and the top is only leaning outwards a little, then some tough trimming, combined with fertilizer and watering, will often bring things back. Remember though, that with the exception of yew trees, conifer evergreens cannot be cut back into bare wood, so there is a limit to how much you can reduce that top. If it is very wide, and an experimental cut shows only bare wood, then it is too late – start planning a replacement.

Gaps can sometimes be successfully filled in. Use the largest plants you can handle, and dig the biggest hole you can. This is difficult if the plants are close together, and you might be better-off removing another plant, just so that you can install a decent replacement. Pay extra attention to that newly-planted bush, and water it well, using liquid fertilizer. It will take a while to develop enough to hold its own against existing plants. Again, of you have lots of gaps, and a generally dilapidated hedge, a complete replacement may be the best long-term option.

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.

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.