Soil and climatic requirements for cultivating tulips
The highest yields come from fertile, humus rich, deeply cultivated soils, pH 6.5 - 7.5. Tulips are grown practically in all types of soils, but it is important that the soils be porous, yet fertile and nourishing.Generally the tulips do not get damaged by frost. This happens only during very cold and snow-less winters, and in case of wrong, too shallow planting of bulbs. The best weather conditions are offered by cool, somewhat rainy autumn, short, mild winter (not below -15 deg. C.) with plenty of snow (at least 5-10 cm) providing excellent insulation against frost. The beginning of spring, as in autumn, should be also mild and cool. During late spring and summer the best conditions would be assured by sparse showers and temperatures within 20 -30 deg. C.
A few word on fertilizing. Manure is to be applied a year before planting. It is scattered every 3 years in autumn, in the amount of 5 - 7 kg per 1m2. In the amateurish conditions it should be dug at the depth of a spade or a little deeper. Cultivation requires an average ploughing, and 2 months later, just before winter, deep ploughing.
Mineral fertilizing is done two or three times, depending on the quality of the soil. It is done straight after planting the bulbs, in spring, on so called green bud, that is directly after first sighs of sprouting. The last fertilizing is done before blooming, best when the flower bud is still very green (a week or two before flowering). The best fertilizer would be of NPK variety (nitrogen-phosphorus-potassium) 10-6-20.