How to Get Rid of Cabbage Root Maggots

As the season changes, in comes the wonderful cooler weather. And with that comes the pests that enjoy munching on the cool weather crops. One common yet stubborn nuisance is the cabbage root maggot. These small little worms can easily take over and devastate your cabbage and other root and cole crops. This seasonal pest is responsible for the destruction of many home gardens. Keep reading to learn how to get rid of cabbage maggots!

How To Get Rid of Cabbage Maggots

Powerful Destruction in One Small Worm

Also known as Delia radicum, common names of the cabbage root fly include cabbage fly and turnip fly. If you’re not careful, the cabbage root maggot can devastate your entire winter crop. Their little bodies are hard to spot, as they feed under the soil. With simple and effective planning, you can control the cabbage root maggot effectively and prevent it from ever returning to your garden. The good news is that this treatment and prevention can be done in a natural and organic way!

How to Identify Cabbage Root Maggots

As with any fly species, the cabbage root maggot represents the larval stage of the same-named fly. The cabbage root fly is a small gray fly that coincidentally looks like a housefly. However, it’s gray, more slender, and has stripes on its body. They’re often found in northern regions.

The cabbage root fly targets the base of cole and root plants to lay their eggs. This often occurs in early spring. Cabbage root fly eggs can only hatch in cool weather. When the eggs hatch, small white worms take over and begin to feed on the plant roots. Cold crops that provide the tastiest food for maggots include cabbage, carrots, beets, broccoli, cauliflower, collards, radishes, rutabagas, turnips, and brussels sprouts.

The maggots are pesky little creatures that can kill young seedling plants as well as stunt older plants’ growth. They are noticeable on seedlings, but not on mature plants, as they stay below the soil line. Maggots are 1/4 of an inch long and are often white or cream-colored.

Symptoms of Cabbage Root Maggot Infestations

Cabbage maggots can be especially difficult to spot. It’s easiest to see their infestation after you’ve harvested the crops. You’ll spot tunnels and holes in them. By that time, however, it’s too late. One of the biggest symptoms is the pests’ impact on the leaves of the plants. The plant will take on a bitter flavor or have a slightly discolored hue. In addition, the leaves of your plants start to wilt, as the damage to the roots is what causes the wilting.

Another way to spot an infestation is by looking for cabbage root flies around your garden in early spring. At this point, you can assume they’re laying eggs and it won’t take long for the cabbage maggots to infest your garden.

How to Remove Cabbage Root Maggots

At this time, there are no effective pesticides nor insecticides that will remove cabbage root maggots completely. Once cabbage maggots have infested your crops, it’s nearly impossible to completely remove them. The best way to avoid cabbage root maggots is to prevent them from ever entering your garden space to begin with. Cabbage root fly control is your best form of removal.

However, you’ve found yourself in a state of infestation. What do you do now? The best method of removal is natural and labor-intensive. You’ll need to pull the plants out and destroy them to stop the maggots from spreading. It’s disheartening, but it’s the only way to extract them and set up your garden properly for prevention.

There is no 100% guaranteed method of keeping away cabbage root flies. However, you can put your best foot forward and take preventative measures by creating an environment that is not amenable to them. The best way to prevent this situation from happening is to prevent the cabbage root fly’s ability to lay eggs in the plants in the first place. You can do this naturally and effectively with minimal effort.

Trap and/or Cover Prevention Methods

The first method of prevention is covering the plants. This will keep cabbage root flies at bay and make it harder for them to lay their eggs on the plant base. Row covers work especially well here. Although this method is less effective once an infestation has occurred, it’s a less manual step for those who haven’t had to deal with this unfortunate situation yet.

Another natural method is to place containers of soapy water nearby. Oily water will work as well. This will attract and trap the cabbage maggot flies and they will drown. Cabbage maggot flies are naturally attracted to the color yellow, so it’s recommended to use yellow containers. Sticky traps are a good way to capture cabbage flies. You can purchase them at most nurseries. You’ll want to place them in and around your garden for the best exposure.

Cabbage collars, or skirts made from cardboard or other useful material, can be placed around the cabbage roots in spring. This protects the roots from the cabbage flies during mating season. In addition, distract maggots by setting up a less valued plant as a trap. For instance, cabbage root maggots are more drawn to radishes. Offset your cabbage crop with radishes. The maggots will be more attracted to the radish and if they infest, you can destroy the radish plant and keep your valuable cabbage crops.

Timing Prevention Methods

Another preventative step is simply planting later in the season. Since cabbage root flies like to lay in early spring, you can wait out their mating season by delaying your planting until later. Late spring or even early summer are your best bets for reducing risk, depending on your climate zone.

You can also prevent cabbage maggots by clearing out all dead vegetation. This will reduce the number of vulnerable areas where the cabbage root fly can deposit their eggs.

Another method of prevention is tilling your garden deeply in late fall. This will help expose and disturb the worms in the soil, making them easier to spot before your crops really start growing. You can wash the maggots off the plant roots and pull out any others you find in the remaining soil. Once you feel you’ve successfully gathered and destroyed their population, you’re safe to return the plants to those beds.

Other Prevention Methods

Practicing crop rotation is another natural prevention step. Crop rotation reduces reliance on one set of nutrients and discourages weeds and pests that take root in one area and populate over time. Move susceptible plants at least once every three years so they can’t cultivate an infestation over time.

You can also look into different varieties of plants. It’s known that many red varieties of the cabbage family have a natural resistance to cabbage maggots.

Finally, create an environment that is a natural enemy for maggots. Using other bugs to fight flies and maggots is a natural defense mechanism. Parasitic wasps are a natural predator of maggots and they can be purchased at nurseries. Nematodes are also effective and can be purchased as well. Once you’re educated on how cabbage maggot flies infest crops, you can take effective measures to prevent them in the future. 

Posted by Amaral Farms

HI and thanks for visiting my blog. I guess I would say I have always been a gardener at heart. My parents gardened and I helped them from a young age. As an adult I took to the organic movement and began gardening using almost exclusively organic methods. My focus has shifted the last decade to add heirloom gardening to the mix. By no means an expert, I do enjoy it and spend at least a few hours a week dedicated to it. I hope you enjoy and gain some value from my blog. Check out my tips for growing tomatoes in pots.