A detailed guide to bonsai chrysanthemum cultivation techniques, comprehensive guidance from planting to care
Chrysanthemum, also known as shouke, is a plant of the genus Chrysanthemum in the family Asteraceae. Chrysanthemums are elegant and noble, with beautiful flower shapes and brilliant colors, and people keep chrysanthemums as ornamental plants. In cultivation, they developed from outdoor open-field growing to pot culture, and chrysanthemums can be grafted onto other plants as rootstock, so the varieties have been greatly developed. Bonsai chrysanthemum cultivation is even more accepted by people, and its main cultivation points are introduced as follows:
1. Selection, cultivation and shaping of rootstock. Use one-year-old Artemisia annua as rootstock, which is characterized by fine branches and a long root lifespan, and is suitable for grafting small chrysanthemums. From mid-to-late April, dig up Artemisia annua seedlings in the wild, taking care to keep the root system intact. After digging them back, pot them in 16 cm pots, water thoroughly, and shade appropriately; afterward, spray water with a fine watering can 1-2 times a day. After the seedlings recover, when Artemisia leaves cover the pot surface, move them to 23 cm pots, taking care to apply sufficient base fertilizer. When the Artemisia grows to 25 cm and has some side branches, it can be shaped. The methods are: natural shaping, laying the flower pot on its side and using the phototropism of Artemisia to make it bend naturally; copper wire binding, holding back water before binding the Artemisia to make the branches soft. Wrap copper wire around the Artemisia branches and then bend them into the desired shape according to the plan. We mostly choose the natural shaping method, and the resulting bonsai shape is natural and healthy. Of course, sometimes the two are also used in combination. The shaping of bonsai chrysanthemums runs through the entire process of their growth. Whether natural shaping or artificial binding, it is not completed all at once; it requires gradual progress and patience and care to achieve the ideal ornamental effect.
2. Selection of scions. The ornamental characteristics of bonsai chrysanthemums require that their scions be varieties basically consistent in flower type, flowering period and growth vigor. Flower colors can be freely matched, otherwise there is no point in talking about ornamental effect. Generally, early-flowering Wujiu chrysanthemum or late-flowering Qiantou chrysanthemum is selected as the scion. They are mostly collected and grafted on the spot at the time of grafting, which can ensure the survival rate.
3. Grafting method. Chrysanthemum grafting is mostly cleft grafting, and bonsai chrysanthemums are no exception. When the side branches formed by the Artemisia grow to 12 cm and their thickness is similar to that of the scion to be grafted, grafting can be done. That is, before the Artemisia branches have become woody, remove 1/2-1/3 of the upper part of the side branch, split it in the middle to a depth of 2-3 cm, then insert the previously wedge-cut scion into the cleft, and the scion and rootstock must be pressed firmly together.
When splitting the rootstock and cutting the scion, be sure to complete it with one cut, so that the cut surface of the scion and the cleft of the rootstock remain smooth; align the phloem on both sides of the scion with the phloem of the rootstock as much as possible. Then pinch tightly by hand, tie well with plastic, requiring moderate tightness, and finally wrap the rootstock and scion with paper to form a trumpet-shaped paper tube, avoiding sunlight to help survival. The grafting time depends on the growth of the Artemisia, generally starting from mid-to-late June and continuing until early July.
4. Cultivation management. Bonsai chrysanthemums are generally planted in 23 cm pots or bonsai pots of the same size. Due to shaping and other reasons, their growth will be affected to some extent. Therefore, water and fertilizer management is extremely important. First, apply sufficient base fertilizer at planting, preferably fully decomposed sesame oil residue. Second, during the peak growing season, apply a thin topdressing once a week. At the same time, take care to remove at any time the sprouting branches of the Artemisia below the scion after the scion survives, so as to ensure the growth of the scion.
Generally, they survive two weeks after grafting, at which point the paper tube can be removed and the binding wire untied. When the scion grows to 5-7 leaves, it can be pinched by leaving 3-5 leaves, and this process can be repeated until final pinching. The final pinching time depends on the ornamental requirements. For general varieties, Qiantou chrysanthemum can bloom 80-90 days after final pinching.
5. Pest and disease control. To control powdery mildew, strengthen management and improve plant disease resistance. Spray thiophanate-methyl and carbendazim at 800 times; dinocap at 2000-4000 times. To control southern blight, disinfect the soil, pull out and burn diseased plants, and keep the pot soil breathable with good drainage. To control leaf miners, spray omethoate at 1000-1500 times in advance for prevention, observe carefully, and handpick them. To control borers, spray omethoate at 1000-1500 times and handpick them. To control nematodes, disinfect the soil.