I lost a lot of my temperate collection to fungus gnat larvae and root rot this last winter. One plant I lost was a Oreophila with 26" pitchers. I've never experienced such decimation before, and I don't want to experience it again. I've cleaned my grow area, removed all the old pots full of rotten bulbs and rhizomes, and I've thoroughly washed everything in preparation for some new plants I ordered. I have my old plants that are still alive (and still infected with fungus gnats) isolated in my unheated greenhouse.
Right now I am repotting my S. Purpurea, I plan to give it new soil, but even after I had thoroughly washed the soil off the roots, I spotted an adult fungus gnat. Sure replacing the soil will help. But I am concerned I need to disinfect the entire plant. Is there some safe way to do this, perhaps submerging the plant in water to drown the larvae and adults?
Also, how do you guys treat plants with fungus gnats, and in what ways can I prevent them.
Has anyone successfully used Azamax? Supposedly it effectively controls spider mites, thrips, fungus gnats, aphids, whiteflies, leaf miners, worms, beetles, leafhoppers, scales, mealy bugs, nematodes and other soil borne pests.