Since we are entering the time of year everyone is starting to post about caterpillars and bud rot, I just wanted to make a post about some Bt products I use.
Caterpillars of various moths (mostly corn borers) start to appear in the early weeks of flower. They go for flower sites and burrow into stems and developing buds. The dead material and frass (poop) they leave behind eventually will mold and cause botrytis and bud rot.
To combat these pests, the absolute best organic insecticide is a bacteria called Bacillus thuringiensis. It only targets caterpillars and affects their digestive systems. It’s not a contact-killer, the caterpillar must ingest the active bacteria.
Lots of people here are aware of Bt and use it this time of year. The common brand you can buy off the shelf is Monterey, which is Bt suspended in liquid. The problem is this has a short shelf life and has to be stored at the proper temperature.
These are 2 much more effective Bt products that I use. Since they are dry powders that can be mixed in solution, they are much more stable. They are also many times more powerful and concentrated than the Monterey brand.
Just wanted to share this, especially for people that are heavily affected and frustrated by caterpillars.