Detailed Explanation of Key Points on Potted Propagation Techniques for Banana Shrub (Michelia figo)

  Banana shrub (Michelia figo), an evergreen shrub, is native to the southern provinces and regions of South China, with wild populations found on Dinghu Mountain in Guangdong. Its bark is grayish-brown, its leaves are leathery, its flowering period is from March to May, and its fruiting period is from July to August.

  According to records in medical texts such as "Compendium of Materia Medica" and scientific verification, drinking herbal teas can not only make people feel joyful and invigorated, but also has the remarkable effects of promoting blood circulation and relaxing muscles, nourishing the skin and improving complexion, strengthening health, and curing diseases while prolonging life. Herbal tea made from banana shrub flowers can remove blood stasis and generate new blood, promote blood circulation and relieve pain, nourish the skin and improve complexion, and has a calming and depression-relieving effect.

  Because the banana shrub's flower opens but does not fully spread, as if smiling but not speaking, this characteristic largely represents the Chinese people's implication of subtlety and suggestion. Therefore, its flower language is ~ subtlety and reserve.

  Spring is indeed a season overflowing with fragrance, and when banana shrub flowers bloom, the fragrance fills the air everywhere. If you still cannot remember the banana shrub, then you must take this opportunity now to smell its fragrance. Its scent is unique and not easily forgotten once smelled, with a faint fragrance of banana syrup. Hakka people must know banana syrup; it is a kind of spice added when eating xianrenban. In other places, xianrenban is called liangfen.

  Banana shrub can be propagated by 4 methods: sowing, grafting, cuttings and layering. Each propagation method is introduced separately here:

  1. Sowing method

  This method is suitable for mass propagation, but the flowering period is late and the flowers are slightly smaller. Seeds can be sown as soon as collected, or stored in sand and sown from late February to early March of the following year. The seedbed should use well-drained sandy loam. For a small amount of sowing, seeds can be sown directly in flower pots. After sowing, cover with coke soil, place in a shaded place, and seedlings can emerge in about 1 month. After emergence, manage as ordinary sown seedlings. Transplant with soil in the spring of the second year.

  2. Grafting method

  For grafting propagation, purple magnolia (Magnolia liliiflora) and Tianmu magnolia (Magnolia amoena) are often used as rootstocks for branch grafting, and it also easily survives. For grafting time, spring grafting should be from late March to early April before banana shrub sprouts. Autumn grafting should be from late September to early October. Autumn-grafted seedlings need strengthened tending, while spring grafting is easier to manage, and the grafting survival rate generally can reach 85%. Grafting generally uses the cut grafting method; the scion should be selected from robust one-year-old branches in the middle and upper parts of the mother tree, 1-2 nodes long, without leaves, and the operation technique follows ordinary cut grafting routine. After cut grafting, to prevent water from soaking into the wound, cover with rice straw, exposing the top shoot; after about 25 days, the scion will heal and begin to sprout. At this time, remove the covering straw and promptly wipe off sprouts on the rootstock.

  3. Cutting method

  Under general conditions, cuttings can be taken at any time except during severe cold in winter and high temperatures in summer.

  This method can propagate more plants in a short period, but growth is slower than grafted seedlings. Spring and summer are suitable times for cuttings. Spring cuttings are taken in late March; select 1-2-year-old branch tips, 10-15 cm long, remove the lower leaves, insert into a seedbed with yellow soil mixed with river sand (6:4) as the substrate. After insertion, shade is required (about 30% light transmittance), keep the bed surface moist frequently, and pot and plant after rooting. For summer cuttings, select semi-lignified branches of the current year, about 8 cm long, using the same method as spring cuttings.

  It should be noted that summer has high temperatures and high air humidity, providing conditions for various diseases to breed. Therefore, the cutting substrate must be disinfected. In addition, if the base of the cuttings can be soaked in 200 ppm indolebutyric acid for 15 minutes, taken out and dried before cutting, it can accelerate rooting and increase the survival rate.

  4. Layering method

  Layering and cutting are actually based on the same principle, both using the ability of branches to grow adventitious roots. Cuttings are carried out separated from the mother plant; although the propagation quantity is larger, the reliability of survival is not as good as layering, and for home propagation generally 2-3 plants are enough, so layering is suitable for home propagation of banana shrub.

  Layering can be carried out at any time during the growth period of banana shrub. But April is suitable; select a 2-year-old branch of appropriate size, well developed, with full and robust tissue, 15-20 cm long. At the selected soil-wrapping and rooting site, make a ring bark girdle 0.5-1 cm wide, reaching the xylem, and apply naphthalene acetic acid at a concentration of about 40 ppm. Then put a suitably sized plastic bag over the girdled part, tie the lower end firmly, fill the bag compactly with moss and culture soil or water-absorbed vermiculite, and leave an opening at the upper end to facilitate watering and ventilation.

  During the maintenance period, pay attention to regularly pouring some water into the bag to ensure a certain humidity, and it must not dry out (but it also must not accumulate water or be too wet). Roots can form after about more than 2 months. After the new roots are fully developed, the young plant can be cut away from the mother plant and planted separately in a pot. After potting, place in a semi-shaded place for 2 weeks, do not fertilize, then let it gradually increase light. After that, gradually carry out water and fertilizer management the same as the mother plant.