A. Growth habit of tulips
Tulip is native to Iran, Turkey and the alpine regions of Tibet in China. Belonging to the lily family tulip genus perennial herbs, bulbs flat conical. Hardy but not heat-resistant, the seed bulbs can withstand a low temperature of -35 ℃. The growth temperature is 15-18℃, and the suitable temperature for flower bud differentiation is 17-23C, and the differentiation is inhibited when the wings are over 35℃.
B. Tulip preferences
Cool, moist, sunny and windy environment, grows better in loose and fertile sandy loam soil. It is a bulbous plant that needs some time of low temperature treatment before it can bloom. Its flowers open during the day with strong sunlight and close at night, and the flowers will also close in cloudy weather. Tulips have a wide range of soil acidity, and can grow normally in a ph value of 6.0-7.8.
C. Tulip conventional open field cultivation
1. Soil requirements
Choose a sheltered, sunny place with loose, fertile soil.
2. Tulips should not planted in heavy clay soil
Before planting, turn the land 35-40cm deep, and disinfect the soil (with 40% formalin, the same method as lily) and improve the soil by applying 2000-3000kg of organic fertilizer per mu. Soil ph value is between 6.5-7.5.
3. Tulip planting
Northern China is generally planted in late September to October. The northeast and northwest temperature drop earlier.
4. Appropriate early planting
In northern China, planting can be done a little later. In Beijing, planting is usually done in mid to late October.
5. Planting too early
The climate is warm, the leaves grow out, and the overwintering need to add mulch to avoid frost.
6. Planting too late
Poor rooting will affect the growth of next year.
7. Planting depth
About 3-5cm, i.e. 3-5cm of topsoil above the top of the ball, with the top buds facing upwards.
D. Management after planting
Water once before planting to make sure the soil is moist during planting.
①After tulip planting
Water again immediately to lower the soil temperature. It can also increase the soil humidity and promote the rooting of tulip bulb base disc. After rooting, the bulb base has a strong root system that can absorb water and nutrients from the soil to maintain the normal growth of the above-ground leaves and stems.
②Before tulip winter
Be sure to water once to prevent frost, and next spring after the young leaves emerge from the soil. Water in time to keep the soil moist. In winter, watering is usually not needed, and the rest of the year is standard to keep the soil moist. A thin liquid fertilizer is applied once during the rapid growth period of the leaves and once at the early stage of bud development to make the flowers big and colorful.
E. Tulip cultivation in greenhouse
Tulip bulbs are first treated with high temperature for a period of time after harvesting. Then they are treated at 5°C for 8-12 weeks. Tulip bulbs treated at 5°C can bloom in 45-60 days in the greenhouse. (But not all tulip bulbs are suitable for the 5°C treatment, so be sure to check each company’s variety catalog before ordering the bulbs)
(1) Soil preparation
The soil in the greenhouse should have good soil structure, good drainage, soil ph between 6.5-7.5 as well as low salt and low nutrient levels. Soil must disinfected before planting with 40% formalin (same method as lilies).
(2) Tulip seed ball treatment
Carefully remove the brown outer skin wrapped around the roots and sterilize them before planting (same method as for lily bulbs). Removing the outer skin can reduce the damage to the roots from the disinfection residue of the bulbs and promote uniform root growth. It makes the whole tulip plant grow evenly and also shortens the cultivation period in the greenhouse. Another method is to plant directly without removing the brown outer skin.
(3) Depth of tulip planting
If you use bulbs with the skin removed, the top of the ball should be slightly exposed; if you use bulbs with the skin not removed, the top of the ball should be 3-4 boxes meters from the soil surface
(4) Tulip planting density
230-280 bulbs/planting density should be smaller for autumn planting. Winter planting, the density should be larger. Depending on the variety, bulb size and planting time, the general crown size of heavy late flowering type. Darwin hybrid type and other varieties, the density is smaller. And early flowering type, can be a little denser.
F. Management after planting
The first two weeks after planting is the rooting stage. Soil temperature should kept at 9-12℃, more than 12℃ will cause blind flowering and reduce the flowering rate. After planting, cover the soil surface with straw or stalks, which can prevent direct sunlight from lowering the soil temperature and play a moisturizing role. If the soil temperature is too high, use cold water to water the ground, and then cover with straw. After two weeks, the greenhouse temperature can gradually increase to 15℃, and after 3-4 weeks, the temperature can rise and maintain 17℃.
Before planting, water once to ensure the soil is moist during planting. After planting, water once to make the seed ball in full contact with the soil to facilitate rooting. The subsequent watering is to ensure that the soil is moist, i.e. the soil below the bulb is grabbed by hand and just squeezed into a ball. The best time for watering is in the morning on a sunny day with drip irrigation. The relative humidity of tulips should never exceed 80%, preferably less than 70%.
Tulips need a lot of nutrients during the budding and budding period. Tulips used for cut flower production are more sensitive to fertilizer.
4. Insufficient fertilizer
Then the stems and leaves grow weakly and the flower stems are soft. After the seed bulbs are well rooted, consider applying some nitrogen fertilizer. Apply 2 kg of calcium nitrate per 100 square meters in 3 applications, one week between each application. The calcium ions in calcium nitrate can also prevent the occurrence of sudden tulip collapse.
5.Tulip bulbs sprouting and new growth
When the buds emerge 2-3cm high, apply 20-8-20 high potassium nitrate fertilizer for all seasons, and 28-14-14 high nitrogen fertilizer.
6.When the tulip buds are formed
Apply another seasonal high potassium nitrate fertilizer to facilitate the flowering of tulips. The stems and leaves are very lush at this time, so do not damage the young stems and leaves during the fertilization operation, and the fertilizer solution should stain the leaves (if you have automatic irrigation equipment, you can use a more efficient and faster water soluble fertilizer).