What are the cultivation methods and precautions for banana shrub (Magnolia figo)?
Banana shrub is also known as Hanxiao Mei, Hanxiao plum, Shanjiezi, white jade orchid, banana flower, etc. It is an evergreen shrub of the genus Michelia in the Magnoliaceae family, native to the southern provinces and regions of South China, with wild populations in Dinghu Mountain, Guangdong, growing in shady slope mixed forests, an aromatic flowering tree, with buds as smooth as jade and fragrance as subtle as orchid. It is mainly grown in pots for ornamental purposes, followed by garden landscaping. Let us take a look at the cultivation methods for banana shrub!
The growing environment of banana shrub
Banana shrub grows in shady slope mixed forests and is especially lush along stream valleys. It likes fertilizer and prefers semi-shade, growing best under weak shade. It dislikes strong direct sunlight, so shade must be provided in summer. Before frost in late autumn, move it into a greenhouse to overwinter at a temperature of around 10°C. Banana shrub is a warm-region woody flowering shrub and is not very cold-hardy; in areas south of the Yangtze River, it can overwinter outdoors in a wind-sheltered, sunny spot. It is not tolerant of dryness and poor soil, but also fears waterlogging, requiring well-drained, fertile, slightly acidic loam; neutral soil can also be adapted to.
Propagation methods of banana shrub
1. Cuttings: Banana shrub cutting propagation is best done from late July to early September. You can take lignified branches that have not yet sprouted new buds but have 3 to 8 leaves, or terminal buds about 15 cm long. Dip the base of the cutting in rooting powder and insert it into sandy soil, then provide appropriate shading and keep the environment moist. Roots will form in about 2 to 3 months, and it can be transplanted the following spring.
2. Air layering: For banana shrub air layering propagation, usually in April select well-developed, plump and robust 2-year-old branches. Make a ring bark cut about 0.5 cm wide at a suitable part of the branch, deep enough to reach the xylem, apply moist moss to the ring-cut area, wrap the outside with plastic film, and tie tightly at the top and bottom. Roots will form in about 2 months. After the new roots have fully developed, cut it off and pot it. After potting, water thoroughly, then water once a day or not at all.
3. Grafting: Banana shrub grafting propagation is best carried out between May and June, often using magnolia as the rootstock, and after surviving it can grow quickly. Banana shrub has thick, fleshy roots and does not tolerate transplanting. If transplanting is truly necessary, it should be done with a large soil ball, and pruning and shaping of the plant are best done before overwintering.
Cultivation methods of banana shrub
1. Soil: Banana shrub has fleshy roots and is not tolerant of dryness and poor soil, but also fears waterlogging. It requires well-drained, fertile, slightly acidic loam; neutral soil can also be adapted to. A culture soil can be made with 4 parts leaf mold, 3 parts garden soil, 2 parts decomposed manure soil, and 1 part sandy soil.
2. Watering: Banana shrub should usually keep the potting soil moist, but must never be too wet. Because its roots are mostly fleshy, too much watering or waterlogging after rain can cause root rot, so humidity must be controlled during the rainy season. During the growing period and before flowering, it needs more water, watering once a day. In high-temperature summer weather, water the leaves to maintain a certain air humidity. In autumn and winter, because sunshine is shorter, watering once or twice a week is sufficient.
3. Sunlight: In summer, banana shrub plants should not be exposed to the sun and need 30% shading to avoid strong light scorching the leaves. They can be placed at an east-facing window or balcony indoors, or outdoors under tree shade or a shade shed. After the autumn cools, it can receive more sunlight. In winter, place it indoors in a sunny, ventilated spot.
4. Temperature: The minimum overwintering temperature for banana shrub should not be lower than 5°C. Once the temperature is below 5°C, the plant's normal physiological activities will be affected, the root's absorption capacity will weaken, and the plant's tender branches and leaves will wilt. At the same time, the maximum temperature should not exceed 15°C. If the temperature is too high, the plant will consume too much internal nutrients, which is unfavorable for the next year's growth. Therefore, in winter, banana shrub is best kept at a room temperature of 5°C to 15°C.
5. Fertilizing: Banana shrub likes fertilizer. Mostly use decomposed cake fertilizer, bone meal, chicken and duck manure, and fish offal and other composted fertilizers diluted with water. During the growing season (April to September), apply fertilizer once about every 15 days. Stop fertilizing during the flowering period and after October. If the leaf color is not bright and deep green, apply one dose of ammonium sulfate water.
6. Pests: Banana shrub often suffers from scale insect damage, which can also induce sooty mold. Scale insects can be removed with a small brush, or sprayed with No. 20 petroleum emulsion diluted 150 times with water. Sooty mold can be prevented and treated by wiping with clean water or spraying with a carbendazim aqueous solution diluted 500 to 1000 times with water.
7. Pruning: Banana shrub should not be pruned excessively. Usually after flowering, prune water sprouts, diseased and weak branches, and overly dense overlapping branches that affect the tree shape, and remove the fruit after flowering to reduce nutrient consumption. Before spring budding, appropriately thin out some old leaves to stimulate new branches and leaves.
8. Repotting: Repot banana shrub once every 1 to 2 years, preferably before new leaves emerge each spring, or after flowering; doing it in autumn is also acceptable. When repotting, remove an appropriate portion of the compacted old soil, replace it with fertile, loose culture soil, remove dead branches and overly long old roots, and place sufficient base fertilizer at the bottom of the pot.