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Do Animals Eat Onion Plants?

Growing your own vegetables can be a satisfying experience. Onions are a particularly common staple for gardeners everywhere. They are sturdy, easy to grow, and aren’t fussy about the type of soil you grow them in. Unfortunately, they are also popular with a variety of animals.

Animals do eat onion plants, and there are several species of them, including squirrels, rabbits, raccoons, dogs, cats, groundhogs, moles, birds, deers, snakes, slugs, snails, and even rats. 

However, while most animals can eat onions, not all of them find onions to be a delectable meal. Read on to find out which animals prefer onion plants so that you can discover what stands between you and a healthy onion crop. 

Animals That Eat Onion Plants

The majority of animals, even in desperation, are likely to walk away from a meal of onions. In fact, some of the animals mentioned above, including cats and dogs, are susceptible to onion poisoning. 

Thanks to strides in evolution, onions developed important essential defenses, such as their acrid odor and harsh taste. However, these advantages aren’t always enough to deter hungry herbivores. If left unchecked, these critters can quickly consume your onion crop, leaving you with nothing for your table. 

Listed below are the species that often prove the most troublesome to onion growers. 

Slugs and Snails

Slugs and snails would welcome an onion dinner, any time. If you find that the tops of your onions are being chewed off, or if some of your onions are bitten in half, these slimy pests could be the culprits. 

Considering the amount of damage these small creatures can inflict, you might be forgiven for thinking that a much larger creature is attacking your onions. Since slugs and snails mostly feed at night, a good way to tell if they are responsible for eating your onions is to go to your onion patch at night and use a flashlight to catch these pesky critters in the act. 

If they are responsible, you can minimize the damage to your plants by using crushed eggshells, gravel chips, or anything with a rough surface around your plants. This will deter the soft-bellied pests from crawling through to your plants. 


Onion is toxic to dogs and cats. According to the ASPCA (American Society for the Prevention of Cruelty to Animals), when ingested, it can cause hemolytic anemia, a condition where the red blood cells break down. This goes for all the plants in the onion family, including shallots, chives, garlic, and leeks. 

Symptoms of onion poisoning include vomiting, diarrhea, panting, rapid heartbeat, and blood in the urine. In the garden, the onion plant sometimes gives off a fragrance that is enticing to dogs and cats. Although they may not dig up the onion roots, they might chew on the plant leaves. 

To prevent this, surround your onions with an enclosure of chicken wire that pets won’t be able to get through. 


Bunnies and rabbits are cute – until they start eating your onions. Other animals that might find your onions appetizing include wild birds, deer, squirrels, gophers, raccoons, mice, and rats. Fortunately, these animals will likely leave your onions alone if there is other scrumptious vegetation available. 

Because of their acrid smell, onions stand a much better chance of surviving these critters than most other plants in your vegetable garden. One way of deterring wildlife from eating your plants is to cover them with boxes or hardware cloth. 


Although onions repel most insects, thrips tend to be particularly problematic, especially in mild climates. They pierce the onion’s tender green shoots and suck out all the juices from the plant. 

Once infested, an onion plant will wilt or turn yellow. In order to combat these tiny insects, you need to spray them off the plants using a steady stream of water. Do this consistently until there is no longer any evidence of these destructive insects. 

Onion Maggots

Onion maggots can be found thriving in the soil surrounding your onion plants. They eat away at your onions, causing the developing bulbs to cease growing and rot. If you discover onion maggots in your garden, use insecticide, soap, or oil to treat the soil. According to Barbara Damrosch, the author of “The Garden Primer,” this is an effective way to get rid of these pests once and for all. 


These are nocturnal caterpillars known for their ferocious appetites. When in large numbers, they can devastate your entire onion crop in one night. Cutworms are about two inches long, gray, black, and brown in color. They hide in the soil during the day, and at night, they crawl up onion plants to feast on the foliage. 

They sometimes snip the plant leaves and drag them underground to eat them in their burrows. If you find yourself facing a cutworm infestation, one way to control them is by going out to your garden each night with a flashlight and removing them by hand. 

Pick the worms off your plants and drop them into a bucket filled with soapy water. If you’re dealing with a large number of cutworms, you may want to apply Bt (Bacillus thuringiensis) in order to cut down the population quickly. 


If you keep chickens, you will need to protect your onion patch from them. The question of whether or not chickens eat onions has been shrouded in mystery for a long time. However, recent studies have shown that chickens can eat onions. None of the plants in the onion family will harm chickens, and in fact, the study shows a boost in the health of chickens that eat onions. 

However, it’s important to note that if you’re keeping backyard chickens, letting them eat onions may have an adverse effect on the taste and quality of their eggs. 


Grasshoppers often appear during summer. They favor onions and mostly feed during the day. However, their camouflage may keep you from noticing them until they have caused considerable damage to your crop. 

Most grasshopper species cut ragged holes in the leaves. Others consume entire leaves at once. And since adult grasshoppers can cover an area of over 15 miles each day during migration, this makes controlling them extremely difficult. 

One way to keep grasshoppers in check is to search for and remove them from your plants by hand. This is most effective if you are dealing with just a few of them. You can also use row covers to keep these ravenous creatures at bay. Just make sure that there are no grasshoppers on your plants before covering your garden. Otherwise, you’ll just be trapping them inside with your onions. 

Copyright article owner is for this article. This post was first published on June 12, 2020.

Onion Flies

Several fly species, including onion flies, can contaminate your onion crop and destroy it virtually overnight. Onion flies lay their eggs near the ground, close to the plant bulb. After the eggs hatch, tiny maggots emerge and start boring into the base of the onion plant, causing large gashes and holes. 

They cut the leaves from the bulb, which stops photosynthesis. As the flies mature, they eat the onion leaves. Unlike most other onion pests, there is no chemical repellent that is effective against these stubborn insects. In order to protect your plants, you will have to physically cover the bulb area using fleece to keep the flies from landing. 


Leafminer eggs live on the onion plant leaves. Once hatched, they fold part of the onion leaf over themselves to hide from predators. They then begin to eat away at the leaf portion beneath them. This continues until autumn when the maggots mature into flies and begin reproducing. 

Similar to the onion flies, leafminers are resistant to chemical deterrents. However, you can successfully remove them from your garden by purchasing beneficial insects like the parasitic wasp diglyphus isaea and releasing them in your garden to handle your leafminer problem. 

Final Thoughts

Now you know all the animals that find your onions as delectable as you do. Use this article as your resource to help you protect your garden from animals that eat onions. 

ReadyToDIY is the owner of this article. This post was published on June 12, 2020.

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