• slide
  • slide
  • slide
  • slide
  • slide
  • slide
  • slide
  • slide

Manage Pests in the Garden with Bacillus thuringiensis

Organic farmers and home gardeners have been using Bacillus thuringiensis, referred to as Bt, for decades to manage pests in the garden. This naturally occurring microbe found in the soil, produces proteins that are toxic to the larva of certain insects.

Bt is sold as a powder, granular, dust or pellet. When the susceptible insect eats it, the toxins become active, the insect stops eating and dies within hours or weeks.

Different strains of this microbe affect different insects. Kurstaki often sold as Dipel or Thuricide kills true caterpillars, the immature stage of moths and butterflies. Use Bt israelensis found in Mosquito Dunks and Bits to kill mosquito and fungus gnat larva.

As always read and follow label directions carefully when using any product.

A bit more information:  Research shows Bt does not harm people or non-susceptible insects when ingested.  Avoid harm to beneficial moths and butterflies with proper timing. Apply it at the proper time and only to plants being damaged by caterpillar pests such as cabbage worms.

Upcoming
Events & Webinars


August 6-16, 2026
Wisconsin State Fair
We Energies Energy Park, West Allis, WI

August 29, 2026
Composting 102
Milwaukee Public Library - East Branch
Register here

Sept. 3, 2026
FREE WEBINAR: 
Tree Planting and Care
Register here

Sept. 11, 2026
Illinois State Master Gardener Conference
Rockford, IL
Register here

Sept. 12, 2026
2026 Knowledge in Bloom Conference
Urban Ecology Center, Milw., WI
Register here

Sept. 17, 2026
FREE WEBINAR:
Fall Landscape Care and Planting

Register here

Sept. 26, 2026
Pruning Hydrangeas & Other Shrubs
Pasquesi Home & Gardens, Lake Bluff, IL

Oct. 6, 2026
Upper Midwest Invasive Species Conference
La Crosse, WI
Register here

WATCH ON-DEMAND WEBINARS

MORE UPCOMING EVENT DETAILS 

Book an Appearance

Learn More

Sign up for Melinda's free newsletter for a chance to win this Milorganite 100th Anniversary prize package.

ENTER NOW