Worm castings owe their pest control capacity to chitinase, an enzyme that breaks down chitin, an integral constituent of insect exoskeletons, fungus cell walls, and nematode eggshells.

The Plant Medic columnist Ricky Kemery says scrawny tomato plants might indicate soil has been depleted of nutrients.

Worm castings owe their pest control capacity to chitinase, an enzyme that breaks down chitin, an integral constituent of insect exoskeletons, fungus cell walls, and nematode eggshells. Chitin is a ...