Kitchen Garden Forum

I share a glasshouse with a friend & we both grow peppers.

The leaves on his have started to turn nasty. 30% of the underneath of the leaf has a brown powdery coating, with occasional white pits (like craters on the moon) which show through as white patches on the upper leaf.

I'd like to find out what it is before it spreads to mine!

Any thoughts?

sounds like some kind of mildew... keep them well watered at the roots (but not humid around the leaves) and well ventilated. A mulch might be a good idea. Make sure they're not overcrowded. Some people spray with 1 part milk to 9 parts water. Or you could use Bordeaux mixture if desperate. Good luck!