Pruning principle: For the whole hedge, the lower branches and leaves should be exposed to sunlight as much as possible to avoid withering due to excessive shading. Therefore, it is best to make the lower part of the crown wider and narrower, usually in the shape of a regular trapezoid or steamed bread. For natural hedgerows, corresponding measures must be taken to adjust the tree potential, renew and rejuvenate according to the habits of different tree species and local climate. From small to large, trim many times, smooth lines, and shape as needed. Generally, the design height of hedges is 60- 150 cm, and those exceeding 150 cm are tall hedges (also called green walls) to isolate the line of sight.

The technical requirements for initial cutting and pruning are as follows: when the hedge grows to 30 cm high, pruning begins. Trim it into prototype 3-5 times according to the design type.

Pruning time: after the second pruning, clean the cut branches and leaves, strengthen the management of fertilizer and water, and carry out the next pruning when the new branches and leaves grow to 4-6 cm. If the interval between trimming before and after is too long, the hedge will be deformed and must be trimmed. Noon, rainy days, strong winds and foggy days are not suitable for pruning.

Trimming operation: At present, large hedge shears are mostly operated by hand, requiring sharp edges to be close to the hedge surface, without missing or repeated shearing, cutting more protruding parts with strong length and less concave parts with weak length, so that straight planes can be trimmed by drawing. Hedges of various shapes (round, ground, fan, Great Wall, etc.). ) according to the type of pruning, cut more at the top and less around.

Setting and pruning: when the hedge grows to meet the design requirements and is set, all new branches and leaves will be cut off at one time to maintain the design specifications.

Most hedges are trimmed according to a certain shape, but for slow-growing tree species, tall bamboo hedges and ornamental flower hedges, most of them are not trimmed, or only the branches on them are adjusted. For hedges that need pruning, the following forms can be constructed: first, single-layer hedges with the same height can be pruned; The second is a two-layer hedge composed of two layers with different heights; The third is multi-layer hedging with more than two layers. From the perspective of shielding effect, two-layer and multi-layer are better, and multi-layer has more changes in spatial effect. Through deliberate pruning, the beauty of hedges can be combined with the beauty of lines, and hedges can be constantly updated to maintain vitality and ornamental value for a long time.

Hedge pruning period and times: Hedge pruning period should be flexibly mastered according to different tree species. For the hedge of evergreen coniferous trees, because the new shoots germinate earlier every year, the first pruning should be completed in late spring and early summer, and cutting materials can be obtained. After beginning of autumn, autumn buds began to grow vigorously again. At this time, it is necessary to carry out a second comprehensive pruning to keep the plants neat and consistent in autumn and winter, and the wounds should be healed before the arrival of severe winter. For most broad-leaved hedges, they can be pruned at any time as needed in spring, summer and autumn. In order to obtain enough cutting materials, it is usually carried out in late spring and early or late growing season. Hedges planted with flowering shrubs are unlikely to be pruned regularly, so it is better to prune them after the flowers wither, so as to avoid a large number of fruits and white shoots from consuming nutrients, promote the differentiation of new flower buds, and prepare for the coming year or later.