Answer: You didn't say how long you've had the plant or how you're caring for it, so it's difficult to pinpoint the problem. I've included some info on potential problems as well as care info. Yellow leaves can be caused by many things including lack of nitrogen, insufficient light, water-logged soil (plant roots need oxygen to thrive), dry soil, or iron deficiency. If the older bottom leaves are yellow, but new growth is green, it's usually a lack of nitrogen. If new leaves are yellow, with green veins, it's usually a lack of iron. Soil should be kept moderately moist (but not wet). Finally, transplant shock can contribute to yellowing. If new growth shows up as green, that might be the problem. Try to isolate each of these possibilities one at a time to determine the problem. Overly wet soils are depleted of oxygen. (As water fills in the minute spaces between soil particles, air moves out.) Plant roots need oxygen to absorb iron in the soil. If you are using correct irrigation methods and symptoms are still present, apply iron chelates or ferrous sulphate to the soil. Both are readily absorbed by a plant?s roots. For about two months after transplanting, keep the soil moist (not wet) around the entire rootball out to the plant's drip line (canopy), so that it can establish a strong root system. Hibiscus are frost-tender, so monitor weather forecasts and protect if frost is predicted. Fertilize in February at the start of the growing season. Hibiscus also prefer acid soil conditions so you might want to use Miracid. Read instructions and follow carefully. Water thoroughly before and after applying any fertilizer to reduce chance of burn. I hope this info helps.
Q&A Library Searching Tips