Monterey Bacillus thuringiensis (BT) 16 oz Concentrate — OMRI‑Listed, Includes Measuring Spoon

Monterey BT is a concentrated, OMRI-listed Bacillus thuringiensis formula that controls caterpillars and worm pests on vegetables, ornamentals and trees when mixed into a spray.

This ready-to-dilute concentrate contains a naturally occurring bacterium that targets specific leaf-eating larvae without harming birds, earthworms or most beneficial insects when used according to label directions. It dissolves easily in water and is packaged with a measuring spoon for accurate dosing, making it suitable for both backyard vegetable plots and larger ornamental plantings.

How does Monterey BT work to protect my plants?

Monterey BT contains strains of Bacillus thuringiensis that, once ingested by susceptible caterpillars and worm pests, disrupt larval feeding and development. It must be applied to foliage where larvae are actively feeding for effective control, and applications are repeated as needed to catch new hatchlings.

• Targets chewing larvae such as cabbage looper, bagworm and gypsy moth
• Applied as a foliar spray so pests ingest treated leaves
• Most effective on young larvae before heavy leaf damage

Is Monterey BT safe for beneficial insects and garden wildlife?

When used according to directions, Monterey BT is selective for caterpillar and worm larvae and does not affect birds, earthworms or many helpful insects like honeybees and ladybugs. Avoid spraying open blossoms when pollinators are actively foraging to minimize any incidental exposure.

• OMRI-listed for organic gardening standards
• No known adverse effects on birds or earthworms when applied properly
• Apply outside peak pollinator activity to reduce contact

What plants and pests can I treat with this concentrate?

Monterey BT is labeled for a broad range of vegetables, ornamentals and shade trees. It controls many common leaf-feeding caterpillars and worms on crops such as broccoli, cabbage, lettuce and tomatoes as well as on ornamentals and shade trees.

• Vegetables: broccoli, cauliflower, lettuce, tomatoes, leafy greens
• Ornamentals & shade trees: controls bagworm, gypsy moth, elm spanworm
• Use on susceptible pests listed on the product label for best results

How do I mix and apply the Monterey BT concentrate?

The concentrate dissolves instantly in water and can be sprayed with a trigger bottle or a pressure sprayer. Use the included measuring spoon for correct dosing, thoroughly cover foliage, and reapply according to the interval on the label until pest pressure subsides.

• Measure dose with included spoon and mix into water
• Apply as full-coverage foliar spray; treat undersides of leaves
• Repeat applications at labeled intervals to control new larvae

Who is this product for? Monterey BT is aimed at home gardeners, market growers and landscapers seeking an OMRI-listed, targeted option for caterpillar and worm pests. It works well for anyone who prefers organic-compatible solutions and needs a concentrate that mixes easily, gives precise application control, and limits impact on non-target wildlife when used as directed.