Why does peacock lettuce have no teeth?

Wrong planting. The pH value of the substrate is too low, which leads to iron and manganese poisoning. Symptoms are necrotic spots and charred edges on old leaves. Seedling raising at low temperature and high humidity lead to epidemic diseases. At first, it showed water stains at the base of the stem, and then it fell and died. Therefore, we should pay attention to temperature and control humidity to avoid diseases. Lack of fertilizer at seedling stage refers to the flowering of plants due to lack of fertilizer at seedling stage, that is, the formation of seedlings and old seedlings.