Repellents are an effective way of controlling deer damage. However, it is important to understand how they work and when to use them. Repellents either taste bad or smell bad. The most effective products do both. With just a bad taste, the deer have to taste the plant to know that it is there. If a product only has a repellent smell component, the deer may feed anyway if they are hungry enough.

Most repellents are not appropriate for food crops!

In areas of high deer density, repellents may be overcome by feeding pressure. To prevent this, it is important to use repellents on valuable and deer-preferred plants only, and then just before time of damage.

Tips for using repellents:

• Read the label
• Shake well before pouring into the sprayer and while applying
• If the product is two parts, stir each part well and then mix the two together
• Use a strainer when pouring into the applicator
• Apply at temperatures about 40 degrees F
• Never store the product where it will heat or freeze (store at 40-90 degrees F)
• Do not apply when plants are wet and follow individual labels for drying time
• Spray each plant thoroughly, just until runoff
• Mix only what you need
• Avoid allowing product to stand in backpack or hand sprayers
• When possible, apply repellent before damage is expected to occur
• To avoid resistance, rotate repellents and only use repellents during appropriate seasons and on appropriate plants
• Repellents should be reapplied to new growth

By Nicole Lemieux and Dr. Brian Maynard, URI Department of Plant Sciences, 1999