I know I have used the same container of BT for 3 or 4 years and it
still seemed to be completely effective against cabbage worms.
I use the dry wetible powder form. I have the feeling you might be
using the liquid.

Steve


Kenneth D. Schillinger wrote:
Here I am in the middle of a Tent Caterpillar infestation and am feeling
frugal.
My question is rather BT (Bacillum Thurengus SP?) will hold over a year or
so. I guess I will find out because I sprayed the critters with the old
spray, but if enough of you reply that BT goes dead in a year I will go out
and buy fresh BT spray.
Thanks, Ken.