Step by step in growing the perfect tulip
To get good results from our bulbs, please follow the following steps. Our specialists are happy to help and guide you at any step of the process:
- Select the right varieties. Not all varieties are suitable for forcing. Varieties may differ in length, speed of growth, amount and position of leaves, preparation-period of the bulbs, etc. AMSONIA can help you to make the right selection.
- Bulbs are stored in our company in well-ventilated coolers at temperatures 17-20 °C. Ventilation with fresh air is essential to avoid high concentrations of ethylene, a gas which is produced by bulbs attacked by fusarium. High concentrations of ethylene may lead to abortion of the central sprout. In general Parrot-types are sensitive for high concentrations of ethylene. Also bigger bulbs are more sensitive than smaller sizes and it also differs per variety.
- Bulbs should be kept dry in boxes providing a good circulation of air at all the time. Humidity should be controlled at all times and should not be more than 75% during the dry storage.
- If bulbs are transported in August-September, transport should be done in temperature-controlled-trucks at 17-20 °C with good ventilation. When bulbs arrive at the growers place, bulbs should be stored also at 17-20 °C in a dry place with good circulation and good ventilation with fresh air! High temperatures and bad ventilation will result in problems during the growth like splitting of the bulb in several small ones and/or abortion of the central sprout.
- After storage at 17-20 °C, bulbs need to receive a period of cooling to break the dormancy. This can be done at the growers place or in the coolers of AMSONIA in Holland.
- Cooling can be done at 9 °C or 5 °C. Cooling at 9 °C usually is done at the growers place, with bulbs already planted in boxes or in the soil of the greenhouse.
- With cooling at 5 ° C the bulbs stay in the boxes which have been received from Holland. Boxes are put in a cooler at 5 °C for around 3 months. Make sure you control the humidity in the cooler to avoid formation of fungus. Humidity in the cooler should not be higher than 85%. After the period of cooling bulbs are planted in the greenhouse, either in boxes or in the soil.
- The optimal period of cooling (9 or 5 °C) is for each variety different and can vary several weeks. Please consult AMSONIA to find out the optimum for each variety.
- If bulbs arrive at your place, make sure you are ready. Provide the right storage at the right temperatures to avoid problems during the growth. If you receive the bulbs in August-September, weather can be hot. If it is too hot and if you don’t have the right storage, please speak to AMSONIA and try to delay the transport.
- After the right period of cooling, bulbs can be put in the greenhouse. Tulips do not require additional light in the winter and the ideal growing-temperature is 12-18 °C. Period of growing depends on the variety and the temperature in the greenhouse.
- Soil should be airy and have a good drainage. Pure peat is not recommended, try to use a mix with e.g. sand. EC around 1,5 and pH between 6 and 7.
- More and more customers who face problems with the quality of the soil, decide to grow the tulips on water (hydro-culture). In basic it works the same as on soil. Please consult AMSONIA on the latest information on this ‘new’ way of growing.
- Do not plant bad bulbs attacked by fusarium. Take them out and destroy them. Bulbs with small mechanical damage usually give normal flowers, unless they are very heavy damaged.
- Important is the formation of good roots. The ideal temperature to make the roots is 9 °C at bulb-level. This may take 2-3 weeks. After formation of the roots the temperature in the greenhouse can go up for further development of the plants. If the cooling is done at 5 °C and bulbs are planted directly into the greenhouse, it is recommended that the skin is taken off at the bottom of the bulbs to make the rooting in the soil easier and quicker.
- Humidity inside the greenhouse should not fluctuate too much and should stay between 65-85%. Make sure you measure this daily! Especially during warm winters humidity inside may reach values which are too high. This may lead to bud-drop, toppling and problems with the leaves. In cold winters humidity inside can be very low.
- Hot air heaters are not recommended to heat the greenhouse. They create big changes in humidity and temperature while switching them on and off. This may lead to problems with the flowers and/or leaves.
- Period of cooling (preparation) and temperature in the greenhouse will have a final effect on the quality of the flowers: longer cooling will give quicker growth with longer stems and smaller buds. Shorter cooling will give slower growth and shorter stems with bigger buds. Higher temperatures in the greenhouse will give quicker growth with less quality. Lower temperatures will give a slower growth but the quality will be better.
- Fertilization has a small effect on the final quality of the flowers due to the short period of growing. Make sure your soil has a basic level of nutrients. After the formation of the roots, add some extra calcium to reduce the risk on scorch, toppling, etc. Important is to use bulbs with a good basic amount of nutrients inside. Bulbs produced on clay-soils in Holland usually have a better amount of nutrients than bulbs produced on sandy soils in Holland. Contact AMSONIA to make sure you will get the right quality of bulbs.
- The majority of the tulips are produced for selling at the 8 of march. If you foresee that your production will be a little late, you can increase the temperature in the greenhouse. This will lead to a quicker growth but will normally lead to less quality plants with a shorter vase-life. If you foresee that your production will be a little early, you can reduce the temperature in the greenhouse. However, be aware of botrytis and make sure that the tulips keep on growing. If the growth stops due to too low temperatures, problems with quality and diseases will occur.
- Good quality tulips will have a good vase-life. Vase-life also depends on the variety. Some varieties are more suitable for long storage. Other varieties open up quickly and are less suitable for longer storage.
- If you cut the flowers, make nice bunches of equal quality. Put them as quick as possible in the cooler at +5 °C. As selling usually is in the winter, high temperatures during transport are not the problem. When it is very cold, make sure that the flowers don’t freeze during transport.
- Instruct your buyer how he or she should store and treat the flowers. Create happy customers as a happy customer will buy again flowers next time!
- After the selling, clean your greenhouse, take out the old parts of the plants including the bulbs. Disinfect your soil and make your greenhouse ready for the next planting.
The guidelines above are just a brief summary of the main issues concerning growing of tulip-flowers. We also have a full manual available about the total process of growing tulipflowers. Please contact Amsonia to get more information.