I've got hybiscus "trees" whose bark is covered in flat, grey-green, dry lichens. They have ruffled edges and cling tightly to the branches and trunks. How do I get rid of the lichens without damaging the hybiscus? They are draining energy and moisture from the plants.
The lichens are absolutely harmless. They are a symptom of other cultural requirements of the plant being impoverished, rather than the problem - their growth rate is simply outpacing the growth rate of your hibiscus, which shouldn't happen if your hibiscus is in good conditions. What are the soil / light / water conditions for your hibiscus?
Unfortunately, I "inherited" them in remarkably poor condition when we bought the house. They were planted in sand, without consistant watering and no fertilization schedule at all. Since I have begun to work with them, ie. daily water, monthly fertilizer, stabilization ropes to help them maintain upright growth (two of them had been blown over by a recent hurricane and were struggling along with trunks tilting 45 degree angles to the ground), they have begun to blossom and to put forth leggy growth. I am keeping them trimmed to encourage thicker foliage and to allow them to spend more strength in establishing better root systems. They are in full sunlight here in Florida and I fertilize once a month with a general flower fertilizer. Is there a specific formulation that would help them more? Thanks. C.
