The days are noticeably lengthening, and where you live the snow may already be melting or gone, and the first signs of spring are in the air. Gardeners everywhere are creeping out from their winter hideaways and getting their gardens ready for another season. Among all that preparation, our evergreens, big and small, specimens, screens or hedges, need some attention too. Let’s look at some of the problems winter may have left, and what steps to take, so that your evergreens can thrive and give you their best.
There are three distinct kinds of winter injury seen on evergreens. First there is physical damage caused by snow, ice and high winds. Branches may have broken off, sections of hedge may have collapsed, or once-compact branches are now dislodged and hang out from the bushes. Each of these things need individual consideration.
The most serious is broken branches, and these need careful assessment. If a branch has broken off completely, then all that can be done is to trim the stump back. Often bark is torn off too, and although not ideal, that will often heal in time. Many people do not realize that limbs of most evergreens won’t re-sprout, unlike most broad-leaf trees and shrubs. As a result, if the section of limb that is left attached to the tree has no significant growth on it, it must be pruned back to the limb it comes from. Only Yew trees can re-sprout from bare branches. Cut back to the slightly thickened ring at the base of a branch, where it meets the larger limb. This ‘collar’ will help heal the wound. Don’t cut back flush with the trunk, and don’t leave a stump. If there is torn bark, trim it off neatly, and trim the edges with a sharp knife back to where the bark is well-attached. This will encourage good healing.
The second kind of winter damage seen on evergreens is winter burn. This shows as brown foliage, and it is visible as soon as the weather warms a little. It is the result of lack of water at the roots, combined with exposure to cold, dry winter winds. If you see it, wait a while, as new growth may emerge from hidden buds. If the area has not greened-up by mid-summer you will have to remove the entire limb that has died. If you have this kind of winter burn, the best protection is to soak your evergreens deeply in late fall, just before the ground freezes. If the winter is dry, without snow cover, you might need to soak again later in the season as well. Mulching will keep the soil around the roots a little warmer, so cover the root-zone in fall, and it will make a significant difference. Use netting, not burlap, and definitely not plastic, to wrap your trees and so reduce water loss.
Finally, salt damage from road salt is all too common in colder areas. This can happen with drifting salt spray from roads, and also from salt water running into the root ball when heavily-salted paths and driveways melt in spring. In both situations the salt sucks water out of the foliage or roots, causing severe browning and death. Try to use gravel and sand on areas adjacent to hedges and evergreens when clearing your driveways, rather than salt. Your plants will thank you for it. For drifting salt, erect a burlap screen a foot or two away from the hedge, to trap the salty spray before it reaches the foliage. Tight wrapping will just hold salty water on the foliage, and only increase the damage.
Spring Pruning and Trimming
Spring is a good season for trimming, as the new growth will quickly make your plants and hedges look fresh and new. A common mistake when trimming evergreens is to create a ‘comb over’ effect by trimming upwards only. This encourages long branches, which are exactly the type that become dislodged from a hedge or trimmed bush during storms. The goal should be shorter, more-or-less horizontal branches, with bushy ends that create the face of the hedge. If you have an older hedge that has been grown the wrong way, you can reduce or even eliminate these upward branches over several seasons, by trimming a few hard back each spring. Cut them back as much as you can, but always leave some leafy branches on them. The gap created will fill in from the surrounding foliage. Take a few out each spring, and soon you will have a much better structure to your hedge.
If you are starting with new plants, always use the trimmers in all directions – up, down and sideways – to prevent these long vertical branches developing. To get the necessary dense branching close to the main trunks, start trimming early. A very common mistake is to wait until plants reach the desired height before starting to trim them. Instead, trim as soon as they produce new growth, shortly after planting. You will not significantly reduce the time it takes to reach the size you want them to be, and you will have much better, longer-lasting hedges and trimmed specimens.
Fertilize Your Plants
If you want to grow your evergreens organically, mulch in late spring with some rich, well-rotted organic material, like compost or animal manures. This will provide all the nutrients needed for healthy growth. If you want to maximize growth, then use a chemical fertilizer high in the element nitrogen, which is needed for leaf and shoot growth. Lawn food works just fine and saves money on a large hedge. Just make sure it has no weed-killer in it. Alternatively, use a blended fertilizer labelled for evergreens. Choose a water-soluble form for young plants, and a granular type for mature plants.
Don’t let weeds grow up against your evergreens, especially young ones. Not only do they compete for water and nutrients, they will reduce growth in that all-important lower area, by shading, and the bottom of your hedge will become thin and bare. Spring is an excellent time to go along and dig up perennial weeds, as the roots are often easier to remove at this time. It is worth the extra time it takes to dig down and take out all the root you can, rather than just pulling the tops off. Mulch will help control weeds, as well as reducing water-loss and providing nutrients. Don’t underestimate the value of rich organic mulches around the garden, they should form the basis of your growing techniques.
Take A Well-earned Rest
After you have dealt with all this, you will need a break, but you can take it knowing that your plants are off to a great start for another season.