Soilless Cultivation Methods and Key Technical Points for Azaleas
The characteristic of soilless cultivation is the replacement of soil with an artificially made substrate.
Summer azaleas grown soilless have a compact crown structure and abundant flowering; large flower diameter and few pests and diseases. It not only improves flower quality but also greatly reduces heavy physical labor, making it a cultivation method worth vigorously promoting. 1. Preparation of the substrate.
Azalea roots are very fine, requiring a loose substrate to facilitate aeration and drainage. Use 1 part vermiculite, 1 part perlite, 1 part river sand, and 1 part coal cinder mixed in proportion. After mixing the substrate, sterilize it with 0.1% carbendazim solution, mix evenly into the substrate, and cover with plastic film for 1 day. Then rinse multiple times with clean water. After air-drying, mix evenly with 0.4% agricultural compound fertilizer solution, cover again with plastic film for one month, and then it can be used for potting.
2. Preparation of the nutrient solution.
Azaleas have relatively strict fertilizer requirements. During the growing period, apply light fertilizer frequently. According to experiments, using agricultural compound fertilizer as the main component, supplemented with trace elements, controlling the pH value at around 5, and spraying low-concentration foliar fertilizer can achieve good results.
Preparation of macronutrients: Add 2 grams of agricultural compound fertilizer and 0.5 grams of magnesium sulfate to 1 liter of water as the standard solution.
Preparation of trace elements: Add 20 grams of disodium EDTA, 15 grams of ferrous sulfate, 4 grams of manganese sulfate, 6 grams of boric acid, 0.2 grams of zinc sulfate, 0.1 grams of copper sulfate, and 0.2 grams of ammonium molybdate to 1 liter of water as the stock solution. When using, add 1 milliliter of trace element stock solution to 1 liter of standard solution to make the full-strength element solution.
Preparation of foliar fertilizer: Add 1 gram of urea, 1 gram of monopotassium phosphate, 0.02 grams of boric acid, and 0.1 grams of vitamin B1 to 1 liter of water.
3. Water and fertilizer management.
Since the substrate has good drainage and aeration but poor water retention, the watering amount should generally be more than soil cultivation, just enough to keep the substrate moist; at this time, it is during bud formation and leaf bud sprouting, requiring a larger amount of fertilizer, so water with full-strength nutrient solution about once every 10 days. From March onward, until the flower buds open, spray foliar fertilizer about once every 15 days. After flowering, water demand is high; besides daily watering, spray water on the leaves in the evening. At this time, fertilizer demand is also high, so it can be changed to watering with nutrient solution once a week and spraying foliar fertilizer once, to promote sturdy new branches and facilitate flower bud differentiation. After the dog days of summer begin, pay attention to keeping the substrate moist and spray water on the leaves; the fertilizer amount can be reduced to watering with nutrient solution about once every 20 days. After the autumn cools, gradually increase the fertilizer amount, apply full-strength nutrient solution about once every half month, and spray foliar fertilizer 1 to 2 times to promote healthy flower bud growth. After winter begins, the physiological activity of azaleas is weak, so fertilization is not suitable; just water appropriately depending on the dryness and wetness of the substrate. During the cultivation process, basically no pests or diseases occurred.