What companion plants should be avoided near carrots?
Written by
Benjamin Miller
Reviewed by
Prof. Samuel Fitzgerald, Ph.D.Strategic companion planting substantially improves the health and yield of carrots by avoiding placement near problematic neighbors. Certain plants attract pests that transmit disease or aggressively compete with carrots. I learned this the hard way after losing an entire crop of carrots to carrot flies because I planted dill nearby. Knowing incompatible pairings would have saved me.
Pest Management
- Trap crops: Plant chervil away from carrots to lure pests
- Repellents: Marigolds emit root chemicals that deter nematodes
- Masking scents: Onions confuse carrot fly navigation
Disease Prevention
- Rotation: Never plant umbellifers in same bed consecutively
- Barrier plants: Garlic chives block airborne fungal spores
- Soil health: Incorporate mustard greens as biofumigants
Space Optimization
- Vertical growers: Use trellised peas for shade without competition
- Shallow rooters: Lettuce makes ideal underplanting
- Timing: Plant quick radishes before slow carrots
Use spatial separation from carrots and companion plants. Keep 12"-18" borders between carrot beds and dill beds. I use rosemary barriers around my carrot plantings. This herb has a strong scent that deters flies and is relatively small. Do not interplant carrots with parsnips, as both can be affected by Alternaria leaf blight.
Keep an eye on pest movement throughout the season. Carrot rust flies can transition between plants in the umbelliferous family, such as parsley and celery. Be sure to pluck or remove volunteer plants immediately. I scouted weekly from July to August. Getting ahead of an infestation will help keep it from spreading throughout your garden.
Good companion plants increase carrot growth tremendously! Onion family plants confuse pests with the scent of carrots. Marigolds reduce nematodes with root exudates. I find that alternating carrot rows with red onions scores me a 70% reduction in pest issues. This gives me healthier carrots and less upkeep.
Read the full article: When to Plant Carrots: Expert Growing Guide
