Flowering Period Control Methods and Techniques for Several Common Flowers
The rise of the flower industry is an important marker of China's economic and social development. Here are several flowering period control techniques for major flowers, for reference.
The chrysanthemum is a short-day plant, and only under short-day conditions will it undergo flower bud differentiation. Therefore, the flowering period can be controlled by regulating day length. To make it flower under long-day conditions, short-day treatment should be carried out. First cultivate the plants until they are robust; when the young shoots grow to 9-12 cm, give only 9-10 hours of light per day, and cover the plants with black cloth or black plastic film for the rest of the time (morning and evening are best, since midday is too hot). The effective perception of short days occurs at the top, so the upper part must be completely dark, while the requirements for the base are less strict. After about 30-40 days of treatment, the chrysanthemum will form flower buds; the covering can then be removed, and fertilizer and water management should be strengthened. To delay flowering, late-flowering varieties can also be chosen, and the method of extending day length can be used to prevent flower bud formation and thus postpone flowering.
To make the tree peony bloom early for the Spring Festival, varieties that bloom early and readily, such as Yufen, Yulouchun and Taohuahong, should be selected. For 5-6 year old plants with strong growth, after leaf fall, pot the tree peony while damaging the root system as little as possible, place it in a spot with low temperature, apply fertilizer once, and then move it into a greenhouse at a room temperature of about 25°C. Spray water on the plants 5-6 times a day, and after leaves emerge spray only the branches and trunk. When the flower buds show color, move them to a low-temperature greenhouse; in this way the flowering period can be maintained for about 20 days. If the normal flowering period of the tree peony is to be delayed, cold storage can be used to extend its dormancy. Keep the temperature above 0°C, and there should be weak light indoors, with 3-4 hours of exposure per day.
Lotus: Lotus mostly blooms from June to August. To make it bloom on National Day, early-flowering varieties that take only about 50 days from cultivation to flowering can be used. Repot the tubs a second time in mid-July, and it can then bloom on National Day. The new lotus rhizomes of late-flowering varieties must be formed in early September, and if they are then planted in a greenhouse with a room temperature above 22°C, the lotus can bloom in winter.
Rhododendron: Rhododendron undergoes flower bud differentiation in autumn. To make it bloom in winter, it can be moved into a greenhouse for cultivation, with the temperature controlled at 20-25°C, and water sprayed frequently on the branches and leaves; in this way it can produce abundant flowers in 1.5 months. If it is to bloom on New Year's Day, then before entering the greenhouse it should first undergo low-temperature treatment at about 0°C for 1-2 weeks. To delay the flowering of rhododendron, it can be kept in a low-temperature state, placed in a cold room, maintained at 1-3°C; if the storage time is long, there should be light indoors. The storage time should preferably be 15-20 days before the desired flowering time.
Camellia: Temperature regulation can be used to promote or delay flowering. To delay flowering, late-flowering varieties should be selected; before storage, the whole plant should be wrapped and bound for cold protection, and placed in a cold storage room at 2-3°C, with about 6 hours of weak light per day. The treatment time is about 1 month, which can achieve the purpose of delaying flowering. For varieties that bloom in spring, after the low-temperature requirement is satisfied, flowering can be advanced simply by heating.
Poinsettia: Poinsettia is a typical short-day plant, so the flowering period can be controlled by regulating the length of the light period. For example, to make it bloom on National Day, short-day treatment can begin in early August for about 40 days, and the beautiful red bracts will then appear in late September. If it is to bloom at New Year, shading is not necessary. If it is later moved into a greenhouse for cultivation, the bracts will turn red naturally. To delay the flowering period, the purpose can be achieved by using lights to lengthen the light period.