How to prune a white magnolia? A detailed guide to the correct pruning method
The white magnolia (Michelia alba) is often used as a street tree and courtyard tree in southern China, while in northern China it is mostly grown as a potted flower. Whether planted in the ground or in a pot, it needs timely pruning: first, to maintain its graceful crown shape, and second, to promote its growth. Below is an introduction to the pruning methods for the white magnolia.
The pruning methods for the white magnolia include branch bending, branch twisting, tip breaking, branch cutting, and chemical control, among others. The technical essentials of each pruning method are described below:
1. Branch bending. This can be done throughout the year, mainly on side branches or small branches on the side branches. By bending the branches to open the branch angle (70 to 90) and change the branch direction, it stimulates new branch growth and flower bud formation.
2. Branch twisting. During its vigorous growth period, take a relatively upright side branch, start from the base of the branch, and bend it by hand toward a more open space until slight cracks appear on the back of the branch. Repeat once after a week.
3. Tip breaking. During the vigorous growth period, pierce the young tender terminal bud of a vigorously growing branch with a needle or cut it with a blade, or pinch it by hand or simply pull out the terminal bud.
4. Branch cutting. If pruning is truly necessary, it should be done in summer when the plant is growing vigorously, choosing a spot where new buds have grown 3 cm to 5 cm, and after cutting, immediately seal the wound with a mud ball mixed with fungicide (such as dexon) and growth hormone (naphthaleneacetic acid), then wrap it tightly with a small plastic film.
5. Chemical control method. During the peak growth period, spray the whole plant with 1500 ppm paclobutrazol.
Depending on the situation, the above methods can be used alone or in combination, such as branch bending after tip breaking; branch bending after paclobutrazol treatment; or branch bending, branch cutting, and branch twisting used together. Practice has shown that, combined with routine care, using the above methods to train and shape the branches can produce a white magnolia with a full, lush plant shape.