Master Gardener Rachelle Kemp’s Tips and Tricks to Rid Gardens of Pests


Summer may be prime gardening season, but autumn’s mild temperatures create ideal conditions for cool-season reapings like lettuce, carrots and cauliflower. These cool-weather crops can make a garden extremely attractive to unwelcome guests. Pests are any living organism which is destructive and invasive to crops, food and livestock, and can come in many shapes and sizes. Depending on the type of pest that has invaded a garden, there are different methods to get rid of them.


Mammals are warm-blooded vertebrate animals distinguished by the possession of hair or fur, mammary glands and the typical birth of live young. They often invade a garden to feed on the plants.

Deer: These animals instinctively know wax myrtle and oleander bushes are poisonous and will not eat them. To keep deer from eating a garden, plant a few of these easy-care bushes nearby. It is important to keep kids and other pets from eating them since all parts of the oleander plant are toxic.

Armadillo: Typically in the southern region, these nocturnal mammals have a leathery armor shell and are notorious for their digging habits. While they can be a nuisance to a garden, they aren’t after the flowers. Armadillos are more interested in the tasty grub worms living in the garden’s soil. Grub worms themselves can ruin a garden by munching on the roots of plants, flowers and grass. To keep out armadillos, first rid the garden of the grubs. Do so by using a granular grub killer, which are available at local garden supply stores nationwide.

Dogs and Cats: While these animals have been domesticated and tamed, they can still wreak havoc on a garden. Dogs like to dig up soil, and cats might use the garden as a litter box. To prevent both behaviors, sprinkle cayenne or chili pepper on the soil. The smell will burn their nostrils so they will stay away. Remember to reapply after rain.

Rabbits: Although cute, rabbits can cause problems by digging holes and eating plants, but there are multiple methods to deter them. The same cayenne or chili pepper method for keeping dogs and cats out can be used. Or, make it difficult for rabbits to hop around by laying down the stems (canes) of thorny plants, such as roses. Line the garden’s perimeter with clipped stems from roses or other thorny plants and spread around the garden bed to make it difficult for rabbits to enter to dig and eat.

Reptiles and Mollusks

Reptiles are cold-blooded animals distinguished by their dry, scaly skin. Most reptiles lay soft-shelled eggs on land. Mollusks have soft, unsegmented bodies and live in aquatic or damp places. Most mollusks have external shells mostly composed of calcium carbonate.

Snakes: These legless reptiles like cooler, shaded soil often found in gardens. To keep them out, try the same thorny stem trick used for rabbits, as it will make it difficult for snakes to slither around. Or, snakes dislike the smell of Sulphur powder, so spread some around in the garden and they will stay away.

Snails and Slugs: These slimy creatures can be kept away from gardens by using the diatomaceous earth (DE) method. This powder is made from the fossilized remains of marine phytoplankton, which dries them out like salt. DE is not harmful for plants or animals, and people can and do eat it. Grain-based foods often contain DE because grains are stored with it to keep bugs from eating the grain. Another method to rid snails and slugs involves an old tuna can, beer and cooking oil. Bury the tuna can halfway into the soil and fill it halfway with the beer and cooking oil. Snails and slugs are drawn to the yeast in beer, so they’ll venture into the can but the oil will prevent them from crawling back out.

Birds, Bats and Rodents

Birds are warm-blooded, egg-laying vertebrate distinguished by the possession of feathers, wings and a beak, and typically being able to fly. Similarly, bats have webbed wings but are classified as mammals. Rodents are also mammals, and they are characterized by their single pair of constantly growing incisors.

Birds and Bats: While they seem like a nuisance, if birds and bats are not eating garden vegetables, keep them around. They love to eat pesky insects that invade gardens. If birds are helping themselves to tomatoes, place red round holiday ornaments around tomato plants. They look like tomatoes, so the birds will peck at them and find they aren’t as easy to eat. If birds are nesting in hanging flower baskets or patio eaves, paint the underside of the front porch a sky blue. People swear by this trick from the Victorian era.

Gophers, Moles and Voles: Gophers and voles like to eat the tasty plants, but moles are more interested in the insects and grubs. A method to rid these rodents from the garden is to use castor oil granules. They don’t hurt the animals but instead send them on their way to another garden. To trap and relocate, find their burrowing site, dig a hole into their tunnel about three feet from the burrow site, and place traps inside both directions of the tunnel.


Insects are small animals with six legs and generally one or two pairs of wings. There are two kinds of insects: piercing/sucking like aphids, also known as plant lice, or chewing insects like beetles, caterpillars or moths.

Piercing/Sucking Insects: For this kind of pest, use an insecticide found at garden supply stores and follow the directions very carefully. Rubbing alcohol can also be sprayed directly on the plant because the insects don’t like the taste of it. Spray early in the morning or late in the evening so the alcohol doesn’t damage the plants.

Chewing Insects: These are a little tougher to get rid of compared to piercing/sucking insects. For chewing insects, a systemic insecticide found at garden supply stores will need to be used. Lady beetles, commonly referred to as ladybugs, eat bad bugs, so it may be a good idea to leave them alone.

Ants: To rid a garden of ants and fire ants, the colony’s queen must first be killed, followed by the worker ants. If not, the mound will just keep returning. If the ants are foraging, a granular ant killer can be used. To test if the ants are foraging, place crushed crackers around the mound about a foot away. Wait 24 hours to see if there is any activity of ants bringing in the cracker crumbs. The DE method used for snails and slugs can also be used since ants have a waxy exoskeleton.

Fleas: The DE method also works for these parasites, or they can be deterred with cedar shavings. Line outdoor pet houses with cedar shavings found at local pet or garden supply stores to keep fleas away from pets.

There are several kinds of pests and ways to get rid of them, so it’s important to know what kind of pest has invaded a garden to best eradicate them. This guide will help to identify the pest and how to treat. It’s important to inspect gardens regularly to detect any pest problems early on.

By Rachelle Kemp, Technical Specialist for The Grounds Guys®

Rachelle Kemp is a Master Gardener with more than 35 years industry experience.


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