Start Up Your Hedge for Spring

After a hard winter, it time to get out and explore the garden, to see how it survived, and if anything is needed. For hedges in particular, winter can be tough, especially if there has been heavy snow, freezing rain, or storms. As well, there are things to do that will give you the best results in the coming growing season, so let’s look at some things you can do that will fire up your hedge for a great season of growth and development. These things are especially important if you planted a hedge last year, in spring or in fall.

Check for Broken Branches

The weight of snow, ice, or simply strong winds can all break branches, especially on older hedges that have perhaps not been trimmed correctly. They may not always be obvious, although of course sometimes they are all too obvious!  The main issue when removing broken branches from evergreens is that most conifer evergreens, like Thuja Green Giant, Emerald Green Arborvitae, Cypress, and others similar plants, is that they cannot regenerate from old wood. That is, branches that don’t have some green shoots on them. So hopefully leaving a thick branch, thinking it will re-sprout, as most trees do, is never going to work. If a breakage has happened below the green parts of the tree, then remove it neatly right back to the main limb it is growing from.

When cutting, leave the collar of bark you will see just where the branch joins on – don’t cut flush. The cut will be bigger with a flush-cut, and take longer to grow bark over, but more importantly, it is likely to cause die-back into the stem and leave permanent damage and weakness. This, by the way, applies to all limb removal from every kind of tree or shrub.

When you have cut away all the damaged parts you can assess your hedge. If you trimmed from an early age you should have lots of branches surrounding the gaping hole where that limb came out, and you will be surprised how quickly even large holes fill in. Smaller gaps will be gone in half a season, larger ones might take two seasons, but go they will.

If however the damage is to the end of a hedge – perhaps a snow-plough ran into it, for example – it is much harder to repair, and there it makes much more sense to take out the last tree entirely, dig the area well, and plant a good-sized replacement.

Mulch Your Hedge

If your hedge is young, or old and showing yellowing and slow growth, then mulch is very beneficial. Use something rich and nutritious, like garden compost or rotted animal manures (cow, sheep or horse) rather than bark chips or shredded bark. Yes, those hard materials last a long time, and they do conserve water and suppress weeds, but they don’t supply any nutrients. Richer organic materials release lots of nutrients as they break down, and for an older hedge they really will rejuvenate it over a few months. For young hedges too, the benefits are terrific, with better soil properties, more beneficial microbial activity in your soil, and nutrients too.

When mulching, keep the material clear of the stems, and don’t bury the foliage either, as it will soon die and brown if it isn’t exposed to light. A layer 2 to 4 inches deep in about right. You don’t need to remove all the old leaves and clippings which often accumulate under hedges, as they will also break down once you had some rich compost.

Fertilize Your Hedge

By far the most important thing to do in spring, especially for a young hedge, is to fertilize it. You can find both older-style chemical fertilizers, and organic-style ones too, and organic ones are especially useful for poorer soils, and of course they don’t involve energy-intensive manufacturing from fossil fuels either. To the plant it makes no difference – by the time they are ready to be absorbed by the roots they have been turned into basic elemental forms – plants don’t absorb vitamins or other complex molecules, since they make them all themselves.

There are three main kinds of fertilizers suitable for hedges – liquid fertilizer, granular fertilizers, and slow-release fertilizers. All three have their uses. Immediately after planting, and for the first season, you will get the best results using liquid fertilizers. These are sold either as concentrated liquids, or powders. Powders are much more economical, and easy to use – just dissolve the recommended amount in water. Young plants have limited root systems, and liquid fertilizers flow right down into the root ball, so they are easily and quickly absorbed, but they need regular application – once a month or even once every two weeks – for best results, as they cannot be concentrated, or the roots will burn.

In the longer term applying liquid fertilizers takes too much time, so after the first season or two, switch to granular forms. These are also more economical. The ordinary types are applied in early spring, mid-summer and early fall. Follow the directions for the amount to apply. Slow-release forms, which look like tiny pebbles, are more expensive, but they only need to be put down once a year. Choose which to use depending on your budget and how much time you have available. Fertilizer in sticks which you drive into the ground is usually not ideal, as it may burn the roots near it, and not spread well to areas further away, producing uneven growth.

Formulations

The fertilizer market is crowded, with many brands all competing for our attention. Forget all that, and instead go straight to the fertilizer formula – the 3 numbers (20-20-20, for example) required by law to be somewhere on the box or bag. If the first number is noticeably bigger than the next two, then that will be fine for a hedge. Even lawn food works on a hedge, although it is not ideal, since it has too much nitrogen (the first number) and not enough of the other nutrients. You want something balanced, but with more nitrogen than anything else. Other nutrients are optional extras, unless you have very sandy soil, where micronutrients can be scarce. If you mulch with that rich organic material we mentioned, then all you need is the nitrogen boost for rapid growth, so don’t worry about the fancy stuff. Check out our blog pages for more detailed blogs on fertilizing hedges.

Watering

In some areas early spring can be dry, with little rain. If that is happening, don’t forget to water your hedge deeply, especially a young hedge. A lot of the annual growth takes place in spring and early summer, and dryness will seriously reduce that, so don’t forget to water.