How to prune lilac

How to prune lilac

Common lilac pruning methods include the following:

Thinning

The degree of thinning is relatively strong, mainly to maintain the shape and growth momentum of the lilac tree, which is conducive to growth and flowering in the second year. Thinning should be done after the leaves fall every year, mainly to remove diseased and insect-infested branches, dead branches, weak branches, inner branches, overlapping branches, and overgrown branches that affect growth and appearance; all small side branches under the main branches need to be cut off; and old large branches should also be cut off to keep uniform gaps between the remaining main branches and a moderate density.

Short

Shortening is light pruning, mainly used to prune plants that do not need to be kept for seeds, thin out the overly dense branches in the inner part, increase ventilation and light transmittance, and accelerate the sprouting of new branches and the formation of flower buds. The inflorescences of lilac are all grown at the top of the branches, and are differentiated into flower buds by the terminal buds. Therefore, after entering the flowering period (except for cutting fresh flowers), they should not be pruned, and should be pruned after the flowers fade. In late spring and early summer every year, when the inflorescence begins to wither, if you do not want to keep seeds, you can cut off the remaining flowers together with the two buds at the bottom of the flower spike to reduce nutrient consumption. If the withered flowers are not cut off, the number of flowers will be greatly reduced in the second year, or even no flowers will appear.

Cut flowers

Lilac has excellent ornamental effects and is an important cut flower for indoor vase cultivation. When cutting flower branches, you must cut them close to the side branches below. Do not climb and break them with your hands, and leave as few stumps as possible. A large, mature lilac bush can provide a large number of cut flowers every spring, but when cutting cut flowers from young lilacs that are blooming for the first time, the number should not be too many, otherwise it will affect the growth of the young tree.

Daily pruning of lilac

During daily pruning, root suckers that are not used for division should be cut off in time, especially for grafted seedlings cultivated with fraxinus, privet and lilac as rootstocks, because a large number of root suckers will be produced from the rootstock every year. If they are not cut off in time, the lilac bushes will often be replaced by the rootstock.

Rejuvenation of old lilac trees

Lilac has strong vitality, and old seedlings can be rejuvenated by one or two renewal methods.

One renewal is to cut off all the branches above the ground of the lilac tree, so that new branches will grow and a new plant will soon be formed. One renewal may affect the appearance, so you can adopt a secondary renewal method, pruning gradually over two years. In the first year, cut off 1/2 of the old branches and keep the other half to maintain the original tree shape. In the second year, cut off the remaining half of the old branches. This will not affect the appearance and can provide assimilated nutrients for the growth of new branches.