Best Bt Spray For Plants: Compare Ready-to-Use and Concentrates

#1 · Best Overall

1. Bonide Captain Jack's Bt

• Form: Spray
• Weight: 2.3 lb

Best for: Ready-to-use garden spray.

Why it ranks #1: Ready-to-use spray targets cabbage loopers, hornworms, and tent caterpillars, and lists use on fruits, vegetables, shade trees, and ornamentals.

Ready-to-use spray is the key convenience here: Bonide Captain Jack’s BT comes in a 32-ounce format that can be applied directly to foliage, without first preparing a mix. Its listed targets include cabbage loopers, hornworms, and tent caterpillars, making it a practical option for gardeners protecting vegetables and ornamentals.

Bonide lists protection for fruits, vegetables, shade trees, and ornamentals, with specific crops including broccoli, kale, peppers, melons, and tomatoes. The ready-to-use format supports direct application, while the verified directions call for shaking well and covering the tops and undersides of leaves. For larger or differently equipped gardens, the product can also be mixed with water for use in a hose-end or pressurized sprayer or mist blower, adding application flexibility.

Skip it if you want a concentrate to mix for your sprayer; Bonide Thuricide BT Concentrate, 16 oz, is a listed alternative.

Choose this Bonide spray for home gardeners who want a ready-to-use option for listed vegetables, fruits, trees, and ornamentals. Its direct-use format suits foliage treatment, while larger-area sprayer use requires mixing it with water.

Listed on Amazon as: Bonide Captain Jack's Bacillus Thuringiensis BT, 32 oz

#2 · Best Concentrate

2. Bonide Thuricide 16 oz

• Form: Spray
• Weight: 1.3 lb

Best for: Bonide concentrate for gardens.

Why it ranks #2: This 16-ounce concentrate targets cabbage loopers, hornworms, and tent caterpillars, with listed use on fruits, vegetables, shade trees, and ornamentals.

A 16-ounce ready-to-mix concentrate sets this Bonide Thuricide BT apart from the brand’s ready-to-use spray, giving gardeners a format intended for preparation before application. Its listed targets include cabbage loopers, hornworms, and tent caterpillars, with coverage for fruits, vegetables, shade trees, and ornamentals.

Bonide names crops including broccoli, cauliflower, kale, peppers, melons, tomatoes, and cabbage, which helps gardeners judge whether it suits their planting. The concentrate format is the key workflow distinction from a ready-to-use spray: buyers prepare it before applying, so follow the product’s directions and protective-gear guidance. The listing states that it controls worms and caterpillar-stage insects while causing no harm to birds, earthworms, or beneficial insects such as honeybees and ladybugs.

Skip it if you want direct application without mixing; Bonide Captain Jack’s BT Ready-to-Use Spray is the closer match.

This Bonide concentrate suits gardeners treating listed crops and ornamentals who prefer a mix-before-use format. It is not the direct-application choice, and buyers should follow its protective-gear and safety directions.

Listed on Amazon as: Bonide Thuricide BT Concentrate, 16 oz Ready-to-Mix Solution for Caterpillar, Worm and Moth Control in Home Garden

#3 · Spoon Included

3. Monterey BT 16 oz

• Form: Oil
• Weight: 16 oz

Best for: 16-ounce concentrate with spoon.

Why it ranks #3: The 16-ounce concentrate comes bundled with a measuring spoon and lists control of cabbage loopers, bagworms, gypsy moths, and other caterpillars.

The bundled measuring spoon is a practical differentiator for Monterey BT’s 16-ounce concentrate: it gives buyers a measuring aid when preparing the product for use. Its listed targets include cabbage loopers, bagworms, and gypsy moths, while its stated plant range spans vegetables, shade trees, and ornamentals.

Monterey names a broad set of caterpillar and worm-type pests, including fall cankerworm and elm spanworm, alongside crops such as broccoli, cabbage, melons, lettuce, and tomatoes. That breadth helps gardeners assess whether the concentrate matches their planting. The included measuring spoon is relevant to preparing measured applications, and the listing says it is safe for earthworms and bees when used as directed. Follow the product’s handling and application directions; the supplied safety information calls for washing after mixing and applying.

Skip it if you want a ready-to-use spray without measuring; Bonide Captain Jack’s BT Ready-to-Use Spray is the better fit.

Choose this Monterey concentrate if you want its listed pest and plant coverage and a spoon included for measuring. It suits buyers comfortable preparing applications; consult the full directions for dilution and safe handling.

Listed on Amazon as: Monterey BT – Bacillus Thuringiensis for Organic Worm and Caterpillar Control Bundled with Measuring Spoon – Concentrate for BT Spray – 16 oz

#4 · Largest Listed Bottle

4. Monterey BT 32 oz

• Form: Oil

Best for: Large Monterey bottle with spoon.

Why it ranks #4: Its 32-ounce size is the largest among the listed Monterey bottles, and the product lists use on vegetables, shade trees, and ornamentals.

The 32-ounce bottle is the defining feature of Monterey B.t. Bacillus Thuringiensis with Spoon, giving buyers the largest listed size among the Monterey options here. Its stated coverage includes several caterpillar and worm-type pests across vegetables, shade trees, and ornamentals, with a measuring spoon included.

Monterey lists cabbage loopers, bagworms, gypsy moths, fall cankerworms, and elm spanworms among its targets, with plant coverage including broccoli, cauliflower, melons, lettuce, and tomatoes. That breadth can help a gardener compare one product against a mixed planting. The included spoon supports measuring during preparation, while the supplied safety information calls for washing after mixing and application and wearing safety glasses or goggles. The 32-ounce format is the distinguishing choice for buyers comparing the listed Monterey sizes.

Skip it if you need a smaller listed Monterey bottle; Monterey B.t. Caterpillar & Worm Killer, 8 oz with Spoon, offers a compact option.

Choose this Monterey product if its broad listed plant and pest coverage matches your garden and you want the 32-ounce format with a spoon. Its larger size may not suit buyers seeking a smaller bottle.

Listed on Amazon as: Monterey B.t. Bacillus Thuringiensis, 32 oz with Spoon

#5

5. Bonide Thuricide 8 oz

• Form: Spray
• Weight: 10.56 oz

Best for: Concentrate for fruit and nuts.

Why it ranks #5: The 8-ounce concentrate names red-humped caterpillars, cabbage loopers, diamondback moths, and other pests, with use on fruits and vegetables.

Listed coverage for nuts as well as vegetables and fruits distinguishes Bonide Thuricide BT Concentrate, 8 oz, for gardeners managing varied plantings. Its named targets include red-humped caterpillars, cabbage loopers, diamondback moths, and tent caterpillars, giving buyers specific pests to compare against their garden needs.

Bonide lists almonds, apples, pears, cherries, grapes, oranges, celery, broccoli, cabbage, and pecans, plus shade trees and ornamentals. That range is useful for shoppers whose plantings extend beyond vegetables. The 8-ounce product is described as a liquid concentrate, so it is a prepare-before-use option rather than a ready-to-use spray. Its listed targets also include omnivorous leaf rollers, making the pest list another practical way to check whether it fits the intended use.

Skip it if you want a ready-to-use option for vegetables and ornamentals; Bonide Captain Jack’s BT Ready-to-Use Spray fits that workflow.

Choose this Bonide concentrate if your garden includes listed fruits or nuts and its named caterpillar targets match your needs. Its 8-ounce format requires preparation, so it is not the direct-spray option.

Listed on Amazon as: Bonide Thuricide BT Concentrate, 8 oz Ready-to-Mix Solution for Caterpillar, Moth and Worm Control in Lawn and Garden

#6

6. Monterey BT 8 oz

• Form: Oil

Best for: Small-format Monterey BT.

Why it ranks #6: This 8-ounce Monterey product includes a spoon and lists caterpillar targets plus use on vegetables, shade trees, and ornamentals.

An 8-ounce bottle with a measuring spoon gives this Monterey B.t. Caterpillar & Worm Killer a smaller listed format than its 16- and 32-ounce Monterey counterparts. The product names a wide range of caterpillar and worm-type targets and plants, making it relevant to gardeners who want that coverage in a more compact bottle.

Monterey lists pests such as cabbage loopers, bagworms, gypsy moths, fall cankerworms, and elm spanworms, as well as vegetables including broccoli, cabbage, cauliflower, melons, and lettuce. That range helps buyers match it to both edible crops and ornamentals. The supplied spoon supports measuring, while the product’s directions emphasize washing after mixing and applying and wearing eye protection. The 8-ounce size is a useful distinction for shoppers comparing Monterey’s listed package sizes.

Skip it if you want a larger listed Monterey bottle; Monterey B.t. Bacillus Thuringiensis, 32 oz with Spoon, offers that size.

This Monterey option fits gardeners seeking its listed pest and foliage coverage in an 8-ounce format with a measuring spoon. Consider whether that quantity suits your application needs, and follow its handling and eye-protection directions.

Listed on Amazon as: Monterey B.t. Caterpillar & Worm Killer, 8 oz with Spoon

#7

7. Southern Ag Thuricide BT

• Form: Liquid
• Weight: 9.9 oz

Best for: Liquid BT caterpillar control.

Why it ranks #7: It is a liquid biological insecticide with the same active ingredient as Dipel, but the supplied details give fewer target pests and plant uses.

A liquid Bacillus thuringiensis formulation is the defining feature of Southern Ag Thuricide BT, giving buyers a clearly identified biological insecticide for certain caterpillar pests. The 16-ounce pint bottle is a straightforward choice for gardeners comparing BT liquids, though the supplied product details do not specify application directions or a crop list.

Southern Ag identifies this product as a biological insecticide made from a bacterium toxic to certain pests, and says its active ingredient is the same as Dipel: Bacillus thuringiensis in liquid form. That information helps shoppers seeking a BT liquid rather than a different type of pest control. The listing provides a 16-ounce pint bottle, but does not give target species, supported plants, or mixing and application instructions, so its stated fit is narrower than products with those details.

Skip it if you need a listed crop range and application directions; Bonide Captain Jack’s BT Ready-to-Use Spray specifies both.

This is a fit for shoppers who specifically want a liquid BT biological insecticide and value knowing its active ingredient. Choose another listing if you need stated target pests, plant coverage, or application guidance before purchase.

Listed on Amazon as: Southern Ag Thuricide BT Caterpillar Control, 16oz – Pint

#8

8. Monterey B.T. gal

• Form: Liquid

Best for: Monterey gallon-size liquid.

Why it ranks #8: The listing identifies a Monterey liquid Bt product and a gallon format, but supplies no target pests, plant uses, or application details.

The gallon-size title distinguishes Monterey B.T. gal from the smaller bottles in this roundup, making it the listed large-format option for shoppers seeking Monterey BT. Its supplied specifications identify the product as a liquid and mark it organic; the available details do not provide pest targets or plant coverage.

The listing supplies three concrete identifiers: Monterey as the brand, a gallon-size title, and liquid as the item form; it also lists organic as a special feature. Together, these facts help buyers distinguish its format and stated attribute when comparing products. However, no target insects, supported plants, mixing directions, or application method are provided in the supplied details. Buyers should use the complete product information to establish whether it suits their garden and how it should be applied.

Skip it if you need named caterpillar targets and crop coverage; Monterey B.t. Bacillus Thuringiensis, 32 oz with Spoon, lists both.

This Monterey listing fits shoppers focused on a gallon-size liquid with organic listed as a feature. Because target pests, plant coverage, and application directions are not supplied here, verify those details before choosing it for a specific garden.

Listed on Amazon as: Monterey B.T. gal