Tips | Things You Absolutely Need to Know About Flower Pruning
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The proverb "70% of flower cultivation depends on management, 30% on pruning" is an important piece of gardening wisdom. Pruning not only ensures even distribution of branches, conserves nutrients, regulates plant vigor, and controls excessive growth, resulting in a neat and beautiful plant shape, but more importantly, it promotes abundant flowering. Most flowers bloom on new shoots; only by continuously pruning old branches can new shoots be encouraged, leading to more flowers and fruit. Pruning generally falls into two categories:
(1) Dormant pruning: This mainly involves thinning and shortening branches. It is best to do this in early spring when the sap is just beginning to flow and the buds are about to sprout. If pruning is done too early, the wounds will not heal easily, and the new shoots will be susceptible to frost damage; if pruning is done too late, the new shoots will have already sprouted, wasting nutrients.
Q
Different types of flowering plants require different pruning times. When pruning flowering plants primarily for their ornamental value, it's essential to understand their specific flowering habits. For spring-flowering plants such as plum blossoms , peach blossoms, and forsythia, flower buds form on the previous year's branches. Therefore, pruning is not advisable in winter or before early spring budding, as this will cut off the flowering branches. Pruning should be done 1-2 weeks after flowering to encourage new shoots, which will then form flowering branches for the following year. If pruning is delayed until autumn or winter, branches with flower buds formed in summer will be damaged, affecting flowering the following year.
Plants that flower on current-year shoots, such as roses, hibiscus, poinsettias , muskmelon trees , kumquats, bitter oranges, and Buddha's hand citrons , should be pruned during their winter dormancy to encourage new shoots, more flowers, and more fruit. Vinylistic woody plants should generally be pruned during dormancy or in winter to maintain a neat, symmetrical, and attractive shape. Plants that primarily grow upright are also often pruned during dormancy.
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Pinching involves pinching (or cutting off) the top of the main stem or side branches of a flower to encourage axillary buds to sprout or inhibit excessive branch growth, resulting in a robust, beautiful plant with an increased number of flowers.
For most herbaceous flowering plants, such as salvia splendens, snapdragons , bell peppers, and periwinkles , pinching off the tips after the seedlings have established themselves and reached a height of about 10 cm can encourage branching and more flowers. Similarly, for plants like begonias , fuchsias , and chrysanthemums , pinching off the tips after the seedlings have established themselves encourages the growth of lateral branches, resulting in a more varied plant shape and increased flower count. However, pinching off the tips of some plants, such as impatiens, cockscomb, and winter jasmine, will cause the flowers to become smaller or prevent them from blooming altogether, and should not be done.
Many woody flowering plants are topped and pinched during repotting in spring or when the main branches are growing vigorously to encourage branching. Examples include pomegranate, rose, plum blossom, poinsettia, bougainvillea, and night- blooming jasmine . Depending on the cultivation purpose and the plant's growth, topping can be done multiple times.
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Shrubs in gardens can generally be divided into three categories: flowering, fruiting, and branch/trunk ornamental. Different pruning methods should be used according to different ornamental purposes. Common flowering shrubs include winter jasmine, forsythia, yellow rose, redbud, and lilac. Their flower buds are formed on the branches of the previous year, so pruning should be carried out in May or June after flowering.
Summer pruning focuses on thinning and shaping branches, removing crossing branches, overgrown branches, dense branches, diseased and insect-infested branches, and dead branches to improve ventilation and light penetration and concentrate nutrients; the remaining branches after flowering can be shortened to promote their growth and encourage more flowering the following year.
For summer-flowering shrubs such as roses, hibiscus, goji berries, and crape myrtles, which bloom on new shoots that emerge in the spring, pruning should be done in winter after leaf fall. Remove overly dense branches, dead branches, and diseased or pest-infested branches. When thinning, the stub should not be left too long; generally, the cut should be made at a 45° angle from the branching point, with a smooth cut. Weak branches should be pruned heavily, while strong branches should be pruned lightly. Each branch can retain 4-6 buds, with the rest cut off.
Shrubs that are valued for both their flowers and fruits, such as holly and honeysuckle, should have some overly dense and diseased branches pruned after flowering to improve ventilation and light penetration, which is beneficial for fruit production. For shrubs valued for their branches and trunks, such as red osier dogwood and kerria japonica, since their main appeal is their vibrant young shoots, they can be heavily pruned every winter, leaving only 15-20 cm of the above-ground portion and cutting off the rest to encourage the growth of more new branches the following year.