Answer: Both nematodes and fungal disease can cause wilt in impatiens; nematodes tend to be more of a problem in the south. To discourage both, be sure to clean up garden debris at the end of the season--pull up plants and destroy (don't compost). Good soil drainage is important; you might want to prepare your planting beds this fall by adding lots of organic matter (compost, well-rotted manure) since this will improve drainage and encourage soil microorganisms that help control nematode populations.
At planting time next spring, be sure to space plants generously to encourage good air circulation; this can help reduce fungal problems. Avoid overwatering, and try keeping mulch away from the base of the plants. And should any plants show signs of the problems, remove them promptly and destroy.
Q&A Library Searching Tips