How to Control Carrot Flies
Carrot flies, or the carrot fly larvae to be more specific is the most destructive pests of carrots. Carrot flies will find your carrots by smell. The adult carrot fly is tiny, no more than 8mm with yellow legs and clear wings. They will lay their eggs near your carrots in the cracks of the soil. The larvae will then feed on your carrots leaving black eaten and damaged spots. They will ruin the look and taste of your carrots.
1. Alliums make great companions for carrots, as the strong allium smell can mask the carrot smell that attracts the flies. Alliums would be garlic, onions, chives, and leeks.
2. Rotate your carrot crops. If you grow your carrots in the same place year after year, you will have more pest problems.
3. Grow your carrots in a polyculture. Don’t make it easy for the pests to find your carrots by growing them in nice neat grocery store rows.
4. Encourage natural predators such as predatory wasps by planting lots of flowers blooming at different times of the year.
5. Row covers can stop the carrot flies from ever laying eggs near your carrots. I personally don’t use them, although row covers for carrots make more sense that say for tomatoes, as you only need to harvest a carrot once, and they do not grow very tall.