no bt is only available in liquid but if you'd rather use a powder i would suggest diatomaceous earth...its usually sold in two forms..one in garden but is difficult find at homedepot/lowes but they also carry in large volumes of 25lb bags in the pool care section.Is BT in brown powder form? I've been given some powder to mix at 1g/litre but so far there's still caterpillars. Used it twice in a week. Neem the rest of grow. Tried Pythrum today. I've got more than 12 plants.