Question
I've been told that cornmeal spread around tomato plants will kill off hornworms. When do I first apply this and how often do I repeat this treatment. Is it a light sprinkle or heavy buildup? Any other suggestions for tomato insects? Thank You,  NORM

Answer
Dear Norm:

I am not familiar with the use of cornmeal to control hornworms.  In checking my available resources, I do not find any available information on its use.  Suggest you use Bt (Bacillus thuringiensis); commercial products include BTR, Caterpillar Attack, Dipel, SOK-Bt, Thuricide, Worm Ender, Caterpillar Killer, and Teknar.

Also, suggest you visit the website listed below that offers an excellent reference guide for organic tomato production:

    http://attra.ncat.org/attra-pub/tomato.html#table3

Regards,

Mack Jean
AllExperts
Master Gardener
Tennessee