Castor Oil for Repelling Critters

Deterring burrowing animals: Best applied after a few fall frosts but can be used year-round.

• For larger areas use a hose-end sprayer. Combine 8 fl oz castor oil with 4 fl oz biodegradable dish soap. Add to the sprayer’s container, and turn the dial to the highest setting. Water the problem area thoroughly, allowing the solution to really sink in.
• For smaller areas use a watering can. Combine 2 T castor oil with 1 T biodegradable dish soap. Mix with 1 gal water. Water thoroughly.

Repelling deer: A strong batch must be sprayed directly on the trees every month or at first sign of nibble during the fast-growth period, but avoid spraying during especially warm summer weather. Can also be sprayed on young trunks to prevent girdling by voles or mice.

• Combine 3 cups castor oil, 1 cup Fish Hydrolysate (8289) and 1 cup biodegradable dish soap; mix well to create a creamy emulsion with no oil bubbles at the surface. During summer months, mix the emulsion into at least 5 gal lukewarm water, and apply with a backpack sprayer. (When first using the spray, test it on small area to make sure the dilution and sprayer are calibrated correctly and don’t burn the foliage!) During months when the trees have no foliage, mix the emulsion into 4 gallons of lukewarm water.

Plant Protection and Last Resorts

These products come with detailed instructions on their labels. Contact us in case you don’t receive the attached booklet or if the label is illegible.

While we try to stay current with product specifications, product formulations are subject to change without notice.

Use our Sprayers to apply these products. We welcome your suggestions about successful low-impact pest-control methods or products.

Is that pesticide registered in your state?

Each state treats potentially dangerous items differently. Like alcohol and open-carry laws, pesticide registrations are different everywhere. We cannot ship a pesticide to a state where it is not registered.

Before buying or using any pest- or disease-control product, be sure it is registered for use in your state and, if you are a commercial grower, registered for commercial production.

Purdue University has a searchable database of information for most states. You can look up products by name, registration number or active ingredient. Contact information is provided for states that don’t participate in the website.

Click here for a chart summarizing the safety of these pesticides for pollinators.

USDA NOP rule concerning disease and pest control
Caution certified-organic growers:

Before using any of these products for pest or disease control, you must have followed the National Organic Program rule 205.206(e). A product being labeled here as allowed is not sufficient to meet standards for organic certification.

Click here for more information and the complete text of the rule.

Organic Certification

Inoculants, soil amendments, fertilizers, livestock supplies and pesticides are labeled as:
OMRI: Organic Materials Review Institute. Most state certifying agencies, including MOFGA, accept OMRI approval.
MOFGA: Reviewed and approved by the Maine Organic Farmers & Gardeners Association Certification Services. Allowed for use on MOFGA-certified farms. Check with your certifier.
WSDA: Listed by the Washington State Department of Agriculture’s Organic Certification division for use in organic agriculture in Washington State. MOFGA has indicated that they will accept products on this list for their certification program. Check with your certifier.
Nat’l List: One-ingredient products on the NOP* List of Allowed Substances (subpart G of the Organic Foods Production Act, sections 205.601-606). Check with your certifier.
AYC: Ask your certifier. Has not been reviewed by a certifier, but the active ingredient is allowed. Ask your certifier.
Not Allowed: A few of the products we list are not allowed for organic production but we think they have a place in sensible agriculture and can be used when certification is not an issue.