By Paul Oliver, Founder, TreeHelp.com

If you’ve ever found your prized tomato plants chewed to bits overnight or your fruit trees covered in leaf-munching caterpillars, you know how frustrating insect infestations can be. Fortunately, there’s a highly effective — and organic-approved — solution that I often recommend to both new and experienced gardeners: Monterey Garden Insect Spray with Spinosad.

This product has earned its place in tool sheds across North America, not only for its powerful control of pests, but also for its low-impact, pollinator-friendly approach. Whether you're dealing with fruit trees, vegetables, ornamentals, or even lawns, this is one of the most versatile and reliable insecticides you can use.

What It Is:

A Natural Yet Powerful Insecticide Spinosad is the star ingredient here — a naturally derived insect control compound developed from soil-dwelling bacteria (Saccharopolyspora spinosa). It’s been around for years and is OMRI-listed for organic gardening, meaning it meets the standards for use in certified organic production.

What makes Spinosad so impressive is that it offers broad-spectrum insect control while being relatively safe for people, pets, and most beneficial insects when used correctly. It works by affecting the insect’s nervous system, causing rapid cessation of feeding and eventual death — typically within 24–48 hours.

What It Works On

Monterey Garden Insect Spray is especially effective on:

• Caterpillars (including cabbage loopers, tomato hornworms, and leafrollers)
• Thrips
• Leafminers
• Fire ants (in lawns)
• Fruit flies
• Flea beetles
• Colorado potato beetle
• European corn borer

One of the main reasons I recommend it is its success in controlling leaf-chewing caterpillars on a wide range of edible and ornamental plants — a major issue for gardeners across North America.

It’s safe for use on:

• Vegetables (tomatoes, peppers, greens, squash, etc.)
• Fruit trees (apples, peaches, citrus, etc.)
• Berries and vines
• Ornamentals and flowers
• Lawns (for surface-feeding pests like fire ants)

How to Use It

Monterey Garden Insect Spray comes as a concentrated liquid that you mix with water and apply using a pump or hose-end sprayer. Here's how I suggest using it:

1. Mix according to label directions. A typical dilution is about 2 tablespoons (1 fl oz) per gallon of water for most uses. Use a clean sprayer to ensure even application. 

2. Apply to the entire plant — especially the undersides of leaves, where pests like to hide and feed.

3. Use in early morning or late evening. This reduces the risk of contact with pollinators and prevents leaf burn under midday sun.

4. Repeat every 7–10 days, or as needed, especially if new infestations occur. For heavy infestations, an initial repeat spray within 3–5 days may be necessary.

When to Apply It

Timing is everything when using Spinosad. Since it's a contact and ingestion insecticide, it's most effective when pests are active and feeding.

• For vegetable gardens, start applications early in the growing season as soon as pests are noticed. 
• For fruit trees, apply just before or during the presence of pests like codling moth larvae or leafrollers.
• On ornamentals, use it as a preventative or at the first sign of damage.

Spinosad breaks down fairly quickly in sunlight, so frequent reapplication may be necessary during peak pest periods — especially after heavy rain or irrigation.

Helpful Tips for Best Results

1. Scout your plants regularly. The sooner you detect pest activity, the more effectively you can intervene.
2. Spray early or late in the day. Spinosad is relatively safe for bees when dry, but avoid applying it when pollinators are actively foraging.
3. Store it properly. Like many biological products, Spinosad should be kept in a cool, dry place away from direct sunlight.
4. Rotate if needed. While Spinosad is very effective, repeated use can lead to resistance in certain pests. Rotate with other organic controls (like neem or pyrethrin) as part of an Integrated Pest Management (IPM) program.

Organic Gardening Bonus

One of the best things about this product is that it fits neatly into an organic or low-impact gardening philosophy. Unlike synthetic chemicals that can have long-term soil and environmental impacts, Spinosad degrades naturally and targets pests with minimal harm to beneficial insects (when used correctly).

It’s even used by many commercial organic growers and is approved for certified production — a big plus for home gardeners who want clean, healthy produce without sacrificing efficacy.

Final Thoughts

Insects are a natural part of any garden, but when populations get out of control, they can do serious damage. Monterey Garden Insect Spray with Spinosad gives gardeners a trusted, effective, and organic-approved option to fight back — without resorting to harsh chemicals or risking beneficial insects.

Whether you’re protecting tomatoes from hornworms, apples from codling moths, or ornamentals from leafminers, this product should be a staple in your garden tool kit. And as always, if you’re unsure about what pest you’re dealing with or how to apply it properly, feel free to reach out to us at TreeHelp.com. We’re here to help your garden grow healthier — with fewer bugs and more peace of mind.