Radishes have several such incompatible neighbours, plants that compete for nutrients, attract the same pests, or exude agents that inhibit radish growth. Learning about the mitigating effects of negative companions can help you avoid wasting space and time. My radishes were stunted for several weeks, until I observed they had been growing next to a row of potatoes! Some of these issues can be remedied by providing proper spacing and choosing the right companions.
Hyssop is known for being allelopathically inhibitory to the growth of nearby radishes. It excretes growth-destroying root substances and should therefore not be planted within at least three feet (90 cm) of a radish bed. I use rosemary instead, which produces similar flowers and foliage without creating any such negative impact. Always seek to plant them in the company of neutral associates, such as marigolds.
Potatoes compete in the nutrient department. Both are heavy feeders on phosphorus and potassium. Radishes lose. Their roots are small. Think of separating your crops by at least 4 ft (120 cm) of carrots or something similar. My garden improved enormously when I added 4-8 inches (10-20cm) strips of carrots between all the crops.
Disease Risks
- Cucumbers: Spread bacterial wilt to radishes
- Melons: Share fungal pathogens
- Prevention: Minimum 5-foot (1.5m) spacing
- Alternative: Plant with corn instead
Pest Management
- Brassicas: Attract flea beetles and aphids
- Kale/Cabbage: Increase root maggot risk
- Barrier: Use floating row covers
- Companion: Grow with nasturtiums
Cucumbers planted too closely together are more susceptible to disease. They are both vulnerable to bacterial wilt and to mosaic virus. For this reason, I separate them by at least 5 feet (1.5 m.) from other crops. I grow sweet corn as a barrier block instead of leaving the ground idle. aiWx If you grow them next to each other, you will have more disease.
Brassica family - Cabbage, kale, and broccoli share flea beetles and root maggots. Determine what you're planting this season, and then wait for pests to proliferate near their last home. Flea beetles will find your cabbages regardless, and then attack your radishes unless you space them accordingly. Aim for at least 6 feet (180cm). Flea beetles can be a problem at any time; use floating row covers. I interplant mine with strong-smelling herbs, such as mint.
Crop rotation on an annual basis will help deter soil problems. Never grow radishes where brassicas were previously located, and revert to legumes for nitrogen enrichment. My three-year cropping plan slayed the healthcare-related issues I experienced. Radishes growing alongside peas will naturally grow more vigorously.
Read the full article: How to Grow Radishes: Foolproof Guide
