Q: Something is eating my plant leaves. My beautiful collard greens were devastated in two day’s time by a caterpillar. What can I do about it organically?

A: You have a fine infestation of cabbage worm (cabbage looper). A small green caterpillar, it’s the he number one pest of cabbage, collards, and kale. A plant can be defoliated in a few days. The holey leaves are a classic garden sight.

I often see lots of caterpillar droppings on leaves and on top of cabbage heads.

The best organic control is Bacillus thuringiensis (B.t.) click for sources) , a natural bacterial control. It is toxic only to caterpillars and does not harm pets or humans.