How to grow azaleas hydroponically? Hydroponic methods and care tips

Soilless cultivation is characterized by replacing soil with an artificially made substrate. The Hunan Provincial Forestry Research Institute used a solid substrate for soilless cultivation of azaleas and achieved very satisfactory results. The variety was the summer azalea (Rhododendron); under soilless cultivation the crown structure was compact, the flowering amount was abundant; the flower diameter was large, and there were few pests and diseases. It not only improved flower quality, but also greatly reduced heavy physical labor, and is 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 pearl sand, 1 part river sand, and 1 part coal cinder mixed in proportion. After mixing, sterilize the substrate with 0.1% carbendazim solution, stir it evenly into the substrate, and cover with plastic film for 1 day. Then rinse multiple times with clean water, and after air-drying, mix evenly with 0.4% agricultural compound fertilizer solution, then cover with plastic film for one month, after which it can be used in pots.

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 a low-concentration foliar fertilizer can achieve good results.

Preparation of macronutrients: add 2 g of agricultural compound fertilizer to 1 L of water, then add 0.5 g of magnesium sulfate; this is the standard solution.

Preparation of trace elements: add 20 g of disodium ethylenediaminetetraacetate, 15 g of ferrous sulfate, 4 g of manganese sulfate, 6 g of boric acid, 0.2 g of zinc sulfate, 0.1 g of copper sulfate, and 0.2 g of ammonium molybdate to 1 L of water as the mother liquor. When using, add 1 mL of trace element mother liquor to 1 L of standard solution; this is the full-strength element solution.

Preparation of foliar fertilizer: add 1 g of urea, 1 g of potassium dihydrogen phosphate, 0.02 g of boric acid, and 0.1 g of V.B1 to 1 L of water.

3. Water and fertilizer management

Because the substrate has good drainage and aeration but poor water retention, the watering amount is generally a bit more than soil cultivation, as long as the substrate is kept moist; at this time it is exactly the bud formation and leaf bud sprouting stage, and the fertilizer requirement is relatively large, so water with full-strength nutrient solution about every 10 days. From March until the flower buds open, spray foliar fertilizer about every 15 days. After flowering, the water requirement is large; besides watering every day, spray water on the leaves in the evening. At this time, the fertilizer requirement is also large, 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 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 every 20 days. After the autumn cools, the fertilizer amount can be gradually increased, applying full-strength nutrient solution about every half month and spraying foliar fertilizer 1-2 times, to promote robust growth of flower buds. After winter begins, the physiological activity of azaleas is weak, so fertilization is not suitable; just water appropriately according to the degree of dryness or moisture of the substrate. During the cultivation process, basically no pests or diseases occurred.