Essential Oils and Garden Pests

garden of vegetablesAre you as excited as I am that gardening season is just around the corner? When you put a lot of love, time and effort into it, it’s heartbreaking when you discover your garden has been attacked by insects, birds or rabbits. And you don’t want to use chemical pesticides on the food you’re going to eat, so how can you naturally protect your plants and your health?

The most common methods are physical barriers, traps, attracting predators, strong smelling herbs and essential oils. I have used some of these methods myself with mixed results. It seems as soon as I sprayed my plants or put out slug traps though, it rained. Arghhh!!! In this blog I will focus mainly on essential oils using my favourite resource, “The Complete Book of Essential Oils and Aromatherapy” by Valerie Ann Worwood.

Although ants don’t cause any damage to your garden, they can be a nuisance. I haven’t had much luck with ant traps or diatomaceous earth. If the nest is far enough away from your plants, you can pour boiling water around the nest with some good success. Insects and animals don’t like strong scents so you can try planting mint, rosemary or thyme around problem areas. You can spray the ground with orange, rosemary, spearmint, peppermint, cinnamon, clove, or thyme essential oils (use 1 drop essential oil per cup of water and shake before using). Alternatively, you can put a couple drops on cotton balls and place them on the ground.

Aphids can do a lot of damage to your plants. They’ve eaten the leaves on our Princess Plum and caused the leaves to curl. You can try spraying the plant leaves with rosemary, spearmint, peppermint, cedarwood, fennel, basil or eucalyptus (using the method above). You can plant plants, such as nasturtiums or potatoes, at the other end of your yard that will attract the aphids away from the plant you’re trying to protect, but I’d rather not attract them at all! You can plant plants that repel aphids such as rosemary, calendula, spearmint or basil around the plants you want to protect. Ladybugs are a common predator of aphids and they are also attracted to calendula. Or you can buy some ladybugs usually around June at some greenhouses. By planting calendula and releasing ladybugs I’ve noticed a decrease in the aphid population that I can live with, and the calendula flowers are attractive!

Cutworms have to be some of the most maddening pests, taking down a whole plant overnight without warning. You can help prevent them by turning over your soil in the spring. If you get cutworms, you can pick them from your plants in the evening and crush them or drop them in a bucket of water. Spray the base of plants with thyme, sage, rosemary, clove or peppermint essential oils diluted in water (as above) or put a few drops on cotton balls and place them around your garden.

Mosquitos won’t cause your plants any harm, but they’ll be a pest to you when you’re working on your garden or just trying to enjoy it. Use a natural bug repellant and plant rosemary, sage, lavender, mint or basil plants in your yard. Put a few drops of citronella, patchouli or clove on cotton balls and place them around you.

Slugs have been the bane of my existence; some years I’ve picked almost 200 of them in a single night/morning. Yuck! I’ve tried crushed eggshells, diatomaceous earth and beer traps without much luck. Planting garlic or chives in or around your garden is supposed to repel slugs. Adding a drop of rosemary to the eggshells is also supposed to help. You can cut coarse sandpaper into strips (or use dried pine needles) and spray them with cedarwood, pine, peppermint, clove or rosemary essential oils and place them around your plants. You can place traps for slugs by partially burying plastic containers (from yogurt, sour cream, etc.) in the soil so the rim is about even with the soil. Pour water into the containers along with two drops of the essential oils mentioned above. And keep the container lids! You can cover your containers when it rains. Apparently slugs really hate garlic so you can place garlic cloves in the ground along the edges of your garden or add 1 tbsp crushed garlic to a watering can and water the perimeter but not the plants.

As long as birds aren’t a pest, you can attract them with feeders and baths, so they’ll feed on your aphids and slugs. If birds are the problem, cover your seeds/seedlings with netting until the plants are established.

I couldn’t find any studies on repelling animal pests, but many gardening websites recommend the following:

  • Rabbits – use garlic or rosemary, lavender or peppermint essential oils on cotton balls
  • Deer – use peppermint or lavender essential oils on cotton balls or garlic
  • Cats – use cinnamon, rosemary, lavender, tangerine, citronella, peppermint, lemongrass or orange essential oils

Refresh with additional essential oils as needed or on a weekly basis.

Have you had any success? What works for you?

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2 comments

Wow, mothballs are so toxic – I hope you don’t have to use them in your vegetable garden!

Deena

Hi Deena! This isn’t likely eco friendly, but I’ve used mothballs to repel animals.
Hope you are doing well. Estelle

Estelle

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