How to Prune Evergreens

Now is the best time to trim evergreens before new growth appears. They can be trimmed at any time, but early spring is the most accepted and convenient time.

Trees and shrubs with needles are what we generally consider evergreens. Rhododendrons, azaleas, and euonymous are evergreens, but these broadleaf varieties should be trimmed after they blossom.

Pruning evergreens helps to control size and shape and thin out the plant. It directs growth and reduces the threat of disease.

The first step in pruning evergreens is to remove any dead or diseased branches and any crossed or close growing limbs. Next trim to set the shape of the evergreen for both height and diameter.

Spruce, taxus, juniper, and arborvitae for the most part will thicken themselves, but the tips may need to be trimmed to control the plants' size and shape. Pine trees should be trimmed in May or June during their growth period. The new branch growth should be pruned halfway back to the point of old growth only during the growing period so new terminal buds will set for the following years growth.

For both spruces and pines, when more than one top appears to be developing, prune away all but one centrally located trunk or leader. An evergreen with two or more trunks is not as strong as one with a single trunk. When windstorms or ice occur, the plant may be torn apart because of being multi-trunked.

For evergreen shrubs, you need to prune in such a way as to thin the plant and force new inner growth rather than just shearing it. Trimming just the outside foliage will prevent the interior foliage from receiving light and the inner branches will eventually die out.

I recommend putting evergreen shrubs on a three-year rotation of gradual renewal pruning. This is accomplished by cutting one branch back to one-third its original size, the one next to it to half its size, and the third to two thirds its length. Do this around the entire perimeter of the plant, cutting back towards the center of the plant. Then, the next year, those cut hardest will be cut least, much like hair thinning shears work, and so on on each year.

Keep in mind the original shape of the plant. If the plant is naturally domed, don't make it conical. If it is naturally a spreading type, don't attempt to force it to grown into an upright one.

Follow these pruning tips and you will keep your evergreens natural looking and can enjoy their beauty for a much longer time.