But it may also be the following reasons:
1, dry, too wet: Milan likes wet, but is also afraid of stagnant water. Therefore, to cultivate Milan's soil, we must cultivate sandy loam with loose ventilation and good drainage, otherwise it will cause root rot and even death. Pay attention to replenish water in time during the growth period, and water the soil surface when it is dry. The ground is often watered to keep the environment moist. If the water quality is alkaline, 0.3% ferrous sulfate (black alum) should be added to neutralize the water.
2. Chemical fertilizer pollution: the growth rate was moderate in July, and the fastest in August ~ 10. After June, we should start pouring 0.2% compound fertilizer around the roots of seedlings, and try not to pour the solution on the leaves to avoid leaf infection.
3. Pests and diseases: In an unventilated environment, orchids are often harmed by scale insects and sooty blotch. If scale insects are found, they can be brushed off immediately, and coal pollution can be sprayed and cleaned, which will eliminate themselves.