Cultivation Techniques and Management Methods for Dwarf Four-Season Chrysanthemums

Dwarf four-season chrysanthemums have a low, compact growth habit and relatively thick, stiff stems that resist lodging, making them suitable for pot cultivation or planting along the front edges of flower beds. They bloom early, have a long flowering period, and are highly tolerant; they are also suitable for year-round cut-flower (cutting) use (for vase arrangements), and are much welcomed for their large blooms, beautiful form, brilliant colors, and strong chrysanthemum fragrance.

1. Variety selection: In recent years, the Dutch Richi series of dwarf four-season chrysanthemums has performed well; when cultivated outdoors in open ground, the flowering period is over 200 days in the north and over 300 days in the south, and they may even bloom year-round, which is why they are also called year-round flowering chrysanthemums. When seedlings are planted in spring, they bloom about 30 days later at a plant height of 15-20 cm. The final plant height is 28-35 cm; a few large-flowered varieties reach a final height of over 50 cm. Shorter varieties have flower diameters of 7-8 cm; taller varieties have flower diameters of over 10 cm. Flower colors include yellow, red, purple, white, and others.

2. Soil and cultivation: Both acidic soil in the south and alkaline soil in the north are acceptable, but a fertile sandy loam mixed with leaf-mold humus from old woodlands is best. Choose small pots with a diameter of 14-16 cm. For large-scale cultivation, plants can first be grown in open fields (for easier management), then lifted with soil into pots when they have grown and are about to show flower buds.

3. Temperature and environment: In early spring it likes light and warmth, in summer it tolerates heat, the flowers are not afraid of sun, and it is also fairly tolerant of shade and cool conditions; in winter it withstands cold, and it can grow normally at temperatures between 7-38°C. The optimal temperature for growth and flowering is 12-35°C, and within this range seedlings can bloom 1 month after planting. During the flowering period it can endure short periods of low temperature at 3-5°C. In the north, after winter begins, when temperatures remain below -3°C for a long time, the main stem withers and the plant enters dormancy; the offshoots around the main stem keep green leaves in winter and can endure short periods of low temperature at -20 to -25°C. For winter flowers in the north, protective cultivation in plastic arched sheds or greenhouses is required. In the Yellow River basin and North China, the plants can overwinter naturally under foggy conditions. In Northeast China, where winter temperatures remain below -15°C for long periods, move the seedlings indoors when a cold wave arrives, or cover them with materials such as arched sheds and straw mats for protection through the winter.

4. Pruning and propagation: 7-10 days after planting, when the seedlings are 8-10 cm tall, pinch the tips, leaving 3-5 branches per plant growing outward at an even slant, and keep only 2-3 flowers per branch. Usually remove spent flowers promptly to conserve nutrients and encourage the formation of new flowers. In the later stage, remove overly dense and overly tall branches to keep the inner canopy ventilated and light-permeable. It has strong propagation capacity; each plant can self-propagate more than 30 seedlings, and it can also be propagated by layering or cuttings.

5. Fertilizer and water management: It prefers dry conditions and fears long-term watering. Normally, water the seedling soil when it looks dry, each time just enough to moisten it thoroughly or half-thoroughly. It must not lack water during the flowering period, but it should not be watered too much or too often. During growth and flowering, about once every month, dig holes away from the seedling roots and bury well-rotted poultry or livestock manure or pressed oilseed cake, etc., applying small amounts several times. In winter, still water when the soil looks dry, and keep the root soil moist so the plant can overwinter safely.

6. Pest and disease control: If aphids or cabbage caterpillars, etc. are found damaging the leaves, spray the leaves with a 1:1500 dilution of pesticides such as "Mie Saoli" or "Kung Fu" to kill the insects. In summer and autumn, during long rainy spells, some leaves are prone to brown spot and powdery mildew, etc.; spray the leaves with a 1:800 dilution of thiophanate-methyl, etc., once every 7 days, and 2-3 sprays will usually control it.