I am sorry for this delayed reply to your gardening question. The spring rush has brought a deluge of questions and we are working hard to catch up!
Hibiscus, like many other plants really does not have a perfect fertilizer. The reason is that depending on your soil and climate, the nutrient mix most needed will vary. For this reason you will often see more than one formulation sold as "Hibiscus Food", "Rose Food", etc. Basically, hibiscus needs a significant amount of potassium (the 3rd number on a fertilizer label), a small amount of phosphorus (the 2nd number), and a moderate amount of nitrogen (the 1st number). Although phosphorus is important in blooming, it builds up in the soil over time and can cause problems with other nutrients if you continue to use a fertilizer high in phosphorus. Some typical examples of the type of nutrient ratios to look for in a hibiscus fertilizer are 18-10-28 and 12-4-15. A product with similar numbers should be a good overall fertilizer for hibiscus.
Thanks for the question. Best wishes for a wonderful gardening season. Please stop in again soon!
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