Thanks Beverly,
I'll check it out.

"Beverly Erlebacher" wrote in message . ..
In article ,
five of four wrote:
I like to grow catnip for my cats. I bought 3 seedlings at a local nursery
and transplanted them into a clean 3 gallon plastic
container, containing Premier pro-mix potting and seeding soil, and put it
outside in the sun..
After about 2 months it was completely overgrown and began to develop a
problem. The bottom leaves began to turn a blotchy white
color. I thought it might be a fungus because it was so overgrown and no
air could get to the bottom leaves. I thinned out the lower
half of the plants, but the problem continued, and has all but destroyed all
of the leaves.
In the meantime I planted some seeds that I had harvested from the plant and
put them in a smaller pot. When they began growing I
made sure that they stayed thinned out and had no leaves touching the soil.
The same thing is happening to these plants, too.
Any idea what the problem might be?

It may be powdery mildew. Unlike many fungal diseases, it doesn't
require much moisture or humidity to spread, and it can really take
over by late summer. I wouldn't recommend fungicides for something
your cats are going to eat. Since you have only a few pots to protect,
you might consider examining them carefully early in the summer and
trying to remove all leaves that show infection, since it will spread
rapidly from leaf to leaf in a plant. The spores are wind-borne so
sanitation may not be very effective.

IIRC, a few years ago some university lab (at Cornell?) came up with a
non-toxic preventive spray containing baking soda, vegetable oil and a
small amount of dish detergent in water. It isn't effective once the
leaves are infected, but it prevented most spores from germinating when
applied frequently. This might be practical for potted plants, but get
the correct recipe since it could damage leaves if it's too strong.