Crape Myrtle Propagation Methods and Causes of Yellowing Leaves

Crape myrtle is a shrub plant, and it is a relatively rare flowering shrub species, with high ornamental value and cultivation value. It is generally seen in courtyard decoration and landscape design, but now it can also be grown in pots.

I. Crape Myrtle Propagation Methods

Seed propagation: Seeds are collected from November to December. Collect seeds with high maturity. After collection, remove the fruit peel, dry them slightly, and store them dry in a container. In March of the second year, they can be broadcast sown or drill sown on the seedbed. After sowing, cover with a layer of fine soil, with the thickness just enough to hide the seeds. To maintain a certain temperature, a small arched shed can be used as cover.

Cutting propagation: For hardwood cuttings, select 1-year-old robust branches and cut them into 15 cm long cuttings. This can be done before the branches sprout, from mid-to-late March to early April. Softwood cuttings are done in July to August. Cut healthy new branches of the current year that are semi-lignified into cuttings about 9 cm long, with a flat cut at the upper end and 2 to 3 leaves retained. Cut the lower end into a horseshoe shape to promote rooting. The cutting depth only needs to reach 3 to 4 cm.

Division propagation: In early March to April, or in autumn, dig out the root suckers of the plant together with the roots, and then plant the new plants obtained.

Layering propagation: This mainly uses air layering, carried out during the growing season. Select 1 to 2 living branches. In March to April, use a grafting knife to score and girdle the branch, cutting deep to the xylem. Dilute rooting powder and apply it to the scored area. After it dries, wrap the scored area with a plastic bag filled with loose garden soil. After watering, tie it tightly. Check after 30 days; once it has survived and rooted, cut it off and plant it.

II. Crape Myrtle Cultivation Methods

Soil: Crape myrtle is vigorous and easy to cultivate, with no strict requirements for soil, but it grows best when planted in deep, fertile sandy loam.

Sunlight: Crape myrtle likes light, and should be planted in a wind-sheltered, sunny place or at the base of a south-facing courtyard wall. Insufficient light not only results in fewer flowers or no flowers, but may even cause weak growth, thin branches, and small leaves.

Watering: Crape myrtle is drought-tolerant and afraid of waterlogging. Each year, before spring growth begins and after leaf fall in autumn, water once with green-up water and once with winter water. At ordinary times, if it is not too dry, there is no need to water. In the rainy season, drainage should be done well to prevent root rot from excessive water.

Fertilizing: Crape myrtle can be fertilized each year after leaf fall in winter and before spring growth begins. Applying human manure or sesame paste residue is even better, which can make the plant grow vigorously the next year, with large and brightly colored flowers.

Pruning: Prune after leaf fall in autumn. Remove overgrown branches, dry dead branches, drooping branches, diseased and pest-infested branches, slender branches, and inward-growing branches. During the young tree stage, side branches on the lower part of the main trunk should also be cut off in time, so that the upper part of the main trunk can receive sufficient nutrients and form a good crown.

Pests: During the growing period, crape myrtle is susceptible to aphids, scale insects, stinging moths, and tortrix moths. If infestation occurs, use 1000-fold diluted dimethoate emulsifiable concentrate to spray and kill scale insects and aphids, and use 1500-fold diluted 80% dichlorvos emulsifiable concentrate to spray and kill stinging moths and tortrix moths.

III. Causes of Yellowing Leaves in Crape Myrtle

Natural aging: One reason for yellowing leaves in crape myrtle is normal metabolism. After growing for a period, some leaves of crape myrtle will turn yellow and fall off due to aging from metabolism. In this case, there is no need to worry; just do a good job with daily care and management.

Overwatering: Crape myrtle is drought-tolerant. If watered too much and the soil is too wet, prolonged water accumulation may cause root oxygen deprivation and root damage, so nutrients cannot be transported to the leaves, causing yellowing. At ordinary times, if it is not too dry, there is no need to water. In the rainy season, drainage should be done well to prevent root rot from excessive water.

Powdery mildew infestation: Powdery mildew is a worldwide☆☆ disease with a very wide host range, and crape myrtle is an important target of its attack. After crape myrtle powdery mildew occurs, it often causes crape myrtle leaves to wither, yellow, and fall off, directly affecting tree vigor and ornamental effect. Pay attention to daily care to improve the plant's disease resistance. When disease occurs during the growing season, spray 500-fold diluted 80% zineb wettable powder, or 1000-fold diluted 70% thiophanate-methyl, or 1500-fold diluted 20% triadimefon emulsifiable concentrate, as well as 800-fold diluted 50% carbendazim wettable powder.

The main control measure to avoid disease and pest infestation in crape myrtle still depends on daily care, such as frequent ventilation and avoiding water accumulation in pots. Only in this way can you grow healthy and beautiful crape myrtles.