I am trying to grow basil in containers with a mix of sphagum peat moss
and perlite (2:1), pH adjusted to 6 with horticultural lime. The last
two times, my plants did not look good after reaching about 4 or 5
inches. They get spots of silvery stuff on the leaves. This is
accompanied by tiny black spots and the plant growth slows to a crawl.
After close inspection, I don't think that it is any kind of insect. I
am feeding with a VERY dilute balanced nutrient solution with
micronutrients with every watering letting top of the soil dry before
watering again. I have also had this problem with my spearmint (although
it doesn't seem to bother the mint much) and patchouli (just starting to
happen here). Any ideas??
--