George Orwell wrote in message
...
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??
--

Silvery stuff? Tiny black spots? Sounds to me like you have spider mite.
They thrive in dry conditions. You could try spraying your plants with a
fine mister, especially under the leaves.

I have a couple of two-foot wooden tubs outdoors (here in U.K.), and in the
spring I throw another few handfuls of growbag (tomato) compost on, to top
them up ('cos it always sinks down a bit through the winter).

In one tub I sprinkle coriander seeds, in the other I sprinkle basil seeds.
Then I put on a rack from a dead refrigerator (to keep the cats off). The
basil seeds came up last week after only 1 day, the coriander is more shy
and takes about a week, it's just poking through now.

I don't feed them with anything, I just water them when they look dry, and
they provide me with leaves until October.

VERY INTERESTED to hear about your growing patchouli. Where can I get some
seeds?

s.