Despite the fact that tulips are now sold almost all year round, own forcing is a lot of pleasure, because it allows you to choose varieties according to your taste, observe the entire process of plant development and get the desired flowering by the desired date.
Due to the low need for lighting, tulips lend themselves well to forcing even under artificial lighting conditions, in the absence of natural light. The decorativeness of flowering in forcing (height, flower size) depends on the variety, the weight of the planted bulb and strict adherence to temperature treatment.
There are two technologies for forcing tulips - 5-degree and 9-degree. The first requires cooling the bulbs at a temperature of + 5 ° C for 12 weeks, followed by planting in the greenhouse soil, while not the slightest deviation from the set temperature is allowed, which cannot be achieved using household refrigerators. Therefore, this technology is acceptable only for industrial floriculture, and we will not dwell on it further.
Tulip bulbs for distillation
Suitable for forcing bulbs 1 parse - 10/11 in a circle or extra - 12 or 12+. In the industrial floriculture of Holland, smaller bulbs of 2 parsing are also used, which are driven out for inexpensive "mix" bouquets. However, the larger the bulbs, the more vigorously the plants develop, the larger the flower turns out and the lower the percentage of non-flowering bulbs.
The full development of the bulb and its readiness for distillation is indicated not only by its size, but also by its weight. A heavy bulb is a sign that it has a flower bud. Smaller bulbs of the first analysis are sometimes more full-bodied than extra bulbs, overfed with nitrogen during cultivation in soil. Bulbs weighing at least 25 g are selected for forcing.
Forced bulbs are widely commercially available, but you can also use your own. To do this, throughout the growing season, it is necessary to provide optimal conditions for the development of plants, to carry out decapitation - removal of flowers at the beginning of pollen maturation. This will increase the percentage of large bulbs. However, proper heat treatment plays a decisive role in preparing tulip bulbs for forcing. In this article, we will not dwell on the process of preparing for forcing our own bulbs, for this it is better to turn to special literature.
Planting tulips for distillation
Tulips are planted for distillation from 1 to 5 October. For distillation for the New Year or in January, the bulbs are cooled for a month at + 9 ° C even before planting.
Before planting, the bulbs are recommended to be cleaned of covering scales for two reasons. Firstly, the roots penetrate into the substrate more easily and the bulb takes root faster, while with dense covering scales, they begin to grow up along the bulb, pushing it out of the soil, which leads to a deterioration in the decorative qualities of the flower. Secondly, removing the scales allows you to identify subtle signs of disease and promptly discard weakly affected bulbs. But with a large number of bulbs, this can not be done, it is enough to free the root tubercle from the covering scales, which often begins to expose itself after cracking of the scales.
Substrate: a mixture of garden soil and river sand in a 1: 1 ratio, you can use pure river sand, peat, sawdust, earth, perlite, but each of these substrates has its own disadvantages. Sawdust does not retain moisture well and requires frequent watering during the rooting period and subsequent cooling. They, like peat, must be deoxidized by adding dolomite flour. The earth is heavy in weight, compacted strongly when irrigated.In the industrial floriculture of Holland, pure river sand or sawdust is used. For amateur flower growers, a mixture of peat and river sand or a mixture of river sand and good garden soil is most acceptable.The substrate should be neutral, with a pH of 6.5-7, and not contain salts that hinder the development of the root system. The presence of nutrients in the substrate is not essential for forcing, but allows you to preserve the bulbs, which are less depleted.
The substrate is poured into the boxes with a layer of 5 cm, slightly compacted and the bulbs are laid out, slightly pressing, at a distance of 0.5-1 cm from each other. The bulbs are poured on top with a layer of 1 cm, watered abundantly. It is better to water with a 0.2% solution of calcium nitrate (20 g per 10 l of water), calcium makes the flower stalks strong. After watering, fill up the substrate to cover the exposed bulbs, because with shallow planting, bulbs bulge during the rooting period.
The density of planting in the ground per 1 square meter of greenhouse area is 250-300 pcs., When using artificial lighting, planting less often - according to the 4x4 cm scheme. Fringed tulips, which require more light, are planted in the same way.
In a pot with a diameter of 12 cm, you can plant from 3 to 5 bulbs, almost close to each other. In this case, the convex part of the bulb must be positioned towards the center so that the first leaf is directed outward and the plants look symmetrically during the flowering period.
Tulip cooling period
Containers with planted bulbs are placed in a room (basement or refrigerator) with a stable temperature of + 9 ° C and an air humidity of 60-70% for rooting. For different varieties, the rooting period can be from 13-14 to 20 weeks. During the cold storage period, the plantings are periodically reviewed and watered. In the event of temperature fluctuations, you can contain growth by covering the plantings with snow instead of watering.
To be placed in a household refrigerator, pots with tulips are pre-packed in a plastic bag.
Tulip distillation technology
Moving boxes with sprouted bulbs into the light should be started when the sprouts reach 5-6 cm, and the flower rudiment will go beyond the storage scales and will be felt in the lower part of the shoot.
Temperature. When transferring boxes to the light, the temperature should not exceed + 12 + 14 ° C. After 3-4 days, the temperature is raised to + 16 + 180C during the day and + 14 + 15oC at night and give full illumination. When the buds begin to color, the temperature is lowered to + 15 ° C. At the same time, the flowering period is extended, the flower becomes large, and the flowering stem is strong and tall. By lowering the temperature during the dyeing period or somewhat earlier, you can bring the flowering to the target date. However, it should be borne in mind that a decrease in temperature during the day by 2.5 ° C from the norm delays the onset of flowering by one day.
In case of a delay in flowering to the target date, an increase in temperature to + 20 ° C can bring flowering closer by 2-3 days.
Lighting: In the first 3-4 days, the lighting is poor. If the sprouts are small - 3-4 cm, then they are shaded with a black non-woven covering material, trying not to touch the sprouts. Shading is removed for 1-1.5 hours every day, and the room is ventilated. In 2-3 days, the sprouts grow up to 6-8 cm, then the shading is removed and full light is given.
Chilled large bulbs require little light when forcing. However, illumination matters and affects the quality of the cut. It has long been established that the illumination of 900 lux is the minimum "threshold" at which all plants bloom. At 800 lux, bulbs of 1 parsing do not bloom.
Even in sunny February, tulips need to extend the daylight hours by 3-5 hours, otherwise the leaves will be poorly colored. For 1 sq. m requires additional illumination of 40-60 W, and the total length of daylight hours should be 10-12 hours. Phytolamps are suspended at a height of 0.5 m and maintain this distance during plant growth.
Watering is done daily in the morning, avoiding water getting on the leaves.
Tulips should be watered with cold water (+ 8 + 12оС), better thawed, because it contains a minimum amount of salts and acids. In the first 7-10 days, it is better to water every other time. 0.2% calcium nitrate solutionwhich promotes the formation of strong peduncles, highly decorative flowers and increases flowering productivity.
Top dressing. The process of forcing bulbous plants is entirely due to the mobilization of nutrients accumulated in the storage scales of the bulb. The forcing period is only 16-30 days, and in a greenhouse feeding do not have time to be absorbed. When cultivating tulips in boxes on poor soil in good lighting conditions, it is still advisable to feed with a special liquid fertilizer for bulbous. However, excess fertilizer causes leaf burns and adversely affects the quality of flowers, and can also delay flowering by 1-6 days.
It has been noticed that feeding 40 g of potash and 20 g of ammonium nitrate per 10 liters of water 10-12 days after attachment helps to preserve the bulbs after forcing.
Plants bloom on average after 3 weeks exceptionally amicably (within 2-3 days) and bloom for 7-10 days. Even with the same planting times and bulb preparation regimes, the period of their flowering, depending on the conditions of the year, can vary within 6 days.. If at the time of staining the buds, the temperature is reduced to + 10 + 12 ° C, then flowering lasts 10-14 days.
Continued in articles: Tulip varieties for distillation,
Tulip varieties for forcing in pots,
Forcing tulips. Flowering acceleration techniques,
Forcing tulips. Cutting and Storage, Forcing Tulips: Reasons for Failure