Detailed Guide to Pot Cultivation Techniques for Dwarf Dahlias

    Because dahlias have a great variety of forms, brilliant colors, a long flowering period, strong adaptability, and are easy to cultivate, they are widely grown in many places. Besides being used to arrange flower beds, they can also be grown in pots for ornamental viewing and used as cut flowers.
 
Cutting propagation This can be done from early spring to summer and autumn, and the survival rate is highest when cuttings are taken in a greenhouse from March to April. Plant the tuberous roots in leaf mold, with the apical buds exposed above the soil surface, and keep the greenhouse temperature at 15°C-22°C. When the apical buds grow to 8 cm, leave one pair of leaves at the base, cut the cuttings, and transfer them to a sand bed. They can root in 15-20 days, and after 30 days they can be potted and may bloom in the same year. You can also, during the stem and leaf growth period, cut stem nodes with axillary buds and insert them into a sand bed; after insertion they root in 15-25 days, with a high survival rate.

Cultivation management After the cuttings have rooted, transplant them. They can be planted in seedling trays with a 5 cm diameter, and the greenhouse temperature should be kept at about 16°C. After 30 days, plant them in pots with a 12-15 cm diameter. Ten days after planting, spray the leaves 1-2 times with 0.05%-0.1% chlormequat to control the height of the dahlias. You can also pinch out the growing tip once when the seedlings are 15 cm tall to increase branching and encourage more flowers. After the flowers fade, remove them promptly. This not only reduces nutrient consumption and prevents the withered flowers from rotting and affecting stem and leaf growth, but also promotes the formation of new flowering branches and prolongs the flowering period. During growth, watering must be strictly controlled to prevent excessive stem and leaf growth and encourage thick stems and large flowers. During high summer temperatures, spraying more water is beneficial to stem and leaf growth, but the potting soil must not be too wet. When the plants begin to wither slightly before frost, cut off the stems and leaves, lift the tubers while leaving 10-15 cm at the base, dry them in the sun for 1-2 days until the surface is slightly dry, then store them dry in a box or bury them in moist sand, keeping the temperature at 5°C-7°C to prevent freezing and to avoid mildew and rot caused by high temperature and humidity.

Pest and disease control The common diseases are powdery mildew and brown spot. In addition to paying attention to ventilation, you can spray a 1000-fold solution of 50% thiophanate-methyl wettable powder. In summer, aphids and red spider mites often cause damage, and you can spray a 1000-fold solution of 40% dicofol emulsifiable concentrate.

Flowering regulation General regulation: choose varieties with different flowering periods and take cuttings in stages. For example, take cuttings of early-flowering varieties in June and late-flowering varieties in late April to early May, so they bloom at National Day. For forcing cultivation: choose early-flowering varieties and plant them in a greenhouse, force sprouting in January, pot them in February, with the nighttime temperature not lower than 15°C and the daytime temperature kept at 20°C-22°C; they can form buds in late March and bloom in early May. Because light is insufficient in late winter and early spring, artificial lighting is also needed to increase the day length to 14 hours. Winter cut flower cultivation: for cut flowers supplied at New Year's Day and Spring Festival, protected cultivation can be used. Choose early-flowering varieties, pinch out the growing tips of the mother plants used for cutting collection in May-June, and keep the new shoots strong for cutting collection. Take cuttings in July, plant them in early August, and pinch out the growing tips in August-September, so they can bloom at New Year's Day. During the high-temperature period in July-August, appropriate shading is advisable; after September, artificial lighting must be carried out to 14 hours per day; when the temperature drops in October, heating is needed, with the nighttime temperature not lower than 8°C, and ventilation is needed when the daytime temperature is above 25°C.