Guide to Analyzing Common Tulip Cultivation Problems
Except in places with alpine climate conditions, tulips grown in open ground for ornamental display can only be planted in autumn and winter and enjoyed in spring; their blooming period is also short, with a single plant flowering for only about 10 days, and withering in 4-5 days when temperatures are high. By appropriately staggering the planting dates and combining varieties with different growth periods, blooming can be extended to about 1 month. The bulbs are extremely cold-hardy and can withstand low temperatures of -35°C in the soil, so ornamental cultivation in open ground is possible almost anywhere in China. Because tulip bulbs are expensive, widespread use for ornamental cultivation in open ground is still not possible at present.
The cultivation techniques for tulips grown in open ground for ornamental display and the requirements for the bulbs are as follows: 1. China's climate conditions determine that in most regions the flowering time for ornamental open-ground cultivation is in spring. The bulbs are planted in the soil in late autumn of the previous year, and the optimal planting time is when the soil temperature at a depth of 15 cm drops to about 9°C. The planting time from north to south in China is from late September to early December. 2. For ornamental open-ground cultivation, the row spacing is 20-25 cm and the plant spacing is about 15 cm. 3. For ornamental open-ground cultivation, the soil covering thickness is 2 times the height of the bulb; shallow covering makes them susceptible to frost damage. 4. The low temperature after flower bud differentiation is complete is a necessary condition for flower bud elongation and flowering; without low temperature, the dormancy of the flower buds cannot be broken. To flower early, artificial low-temperature treatment must be carried out after flower bud differentiation. Those treated at 5°C are called "5°C bulbs," those treated at 9°C are called "9°C bulbs," and untreated ones are called "ambient bulbs" or "ordinary bulbs." Except in regions where the winter soil temperature is above 5°C, ornamental open-ground cultivation does not use bulbs that have undergone 5°C or 9°C low-temperature treatment, in order to save production costs. When cultivating "5°C bulbs," the soil temperature at 5-10 cm must remain below 10°C for 2 weeks, after which the soil temperature rises to 15°C-16°C; after planting "9°C bulbs," they must have 6 weeks of low-temperature treatment or go through a natural low-temperature period.
After flowering, the spent flowers should be cut off promptly, water and fertilizer management should be strengthened, and weeds should be pulled out to promote bulb growth. Under the climate conditions of most places, the bulbs degenerate relatively quickly, and they should be discarded after 2-3 years of cultivation.