Detailed Explanation of Key Fertilization Techniques for Lilies and Roses

Ms. Xi from Quanjiao, Anhui, asks: I grow lilies for their bulbs. How should I fertilize them to achieve high quality and high yield?

Expert: Lilies are perennial plants and should be given heavy applications of organic fertilizer. The seedling stage is relatively long, so organic fertilizer should be the mainstay, reasonably combined with nitrogen, phosphorus and potassium chemical fertilizers. First, choose a sandy loam soil with deep soil layers and good drainage. Before planting, in conjunction with deep plowing and soil preparation, apply 2000-3000 kg of decomposed organic fertilizer, 10 kg of urea, 20-30 kg of superphosphate, and 10-15 kg of potash fertilizer per mu. Topdressing is divided into three applications, applied in conjunction with shallow plowing and weeding, and covered with soil after application. The first is after the seedlings emerge uniformly in spring, applying 1000-2000 kg of decomposed 20% human and livestock manure water per mu, or 10 kg of urea, 20-30 kg of superphosphate, and 10-15 kg of potash fertilizer. The second is before flowering, applying 5000 kg of decomposed human and livestock manure water or 30-40 kg of general-purpose compound fertilizer per mu. The third is after flowering, applying 30 kg of high-nitrogen-potassium compound fertilizer per mu. In the middle and late stages, spraying 0.2% monopotassium phosphate or 0.3%-0.5% urea several times as appropriate is also very effective.

Mr. Qi from Changsha, Hunan, asks: When growing lilies, we also pinch off the growing tips and remove flower buds. What is the purpose? Is it related to fertilization?

Expert: Pinching off the growing tips and removing flower buds can control the growth of lilies, promote the transfer of nutrients to the underground bulbs, and increase bulb yield. Research shows that, in conjunction with fertilization and irrigation, proper pinching of growing tips can increase bulb yield by 8%-10%.

Ms. Gao from Shangqiu, Henan, asks: I have contracted several hundred mu of land to cultivate roses. How should I fertilize them?

Expert: Roses are upright shrubs, and the cultivation goal is to produce glossy green leaves and brightly colored flowers. For this purpose, fertilization should be based mainly on organic fertilizer, with organic fertilizer combined with nitrogen, phosphorus and potassium chemical fertilizers. The supply of medium and trace elements such as magnesium, iron and boron should also be considered. Different cultivation methods such as home potting, greenhouse and open-field cultivation have different fertilization requirements. For densely planted rose gardens used for cut flowers, dig trenches or pits 50-60 cm deep, and apply 4000-6000 kg of decomposed barnyard manure, compost and other organic fertilizers, 30-50 kg of superphosphate, or 8-12 kg of diammonium phosphate, and 5-10 kg of potash fertilizer per mu.

Ms. Liu from Beijing asks: How should topdressing be carried out for roses? What issues should be noted when fertilizing?

Expert: After roses are planted, apply different fertilizers according to the nutrient requirements at different stages. From after bud break in spring to before overwintering, at 20-25 cm around the tree, in conjunction with shallow plowing and weeding or irrigation, apply decomposed human and livestock manure water, chemical fertilizer solution or dry chemical fertilizer. Apply 2-3 times per month, with 40-50 g of chemical fertilizer per plant each time. For the nitrogen-phosphorus-potassium ratio of the chemical fertilizer, before flowering, nitrogen and phosphorus should be dominant; after flowering, phosphorus and potassium should be dominant; in autumn, nitrogen fertilizer should not be applied too much, otherwise it will affect safe overwintering. For example, the fertilization formula ratio during the flowering period is 1 kg of urea, 2 kg of superphosphate, and 2 kg of potassium sulfate, mixed to make a 0.2% chemical fertilizer solution. It can also be prepared with high-nitrogen-potassium compound fertilizer, and the concentration of foliar fertilizer generally does not exceed 0.2%. Spray in the morning or evening on sunny days, and avoid midday on sunny days and rainy days. Apply once every 7-10 days. Be very careful not to get the fertilizer solution on flower buds, flowers or leaves; do not fertilize during full bloom or just after pruning; it is best to apply it between two flowering periods.