The main plants to avoid near cauliflower are strawberries, other brassicas, and heavy feeders. These plants cause problems through pest sharing or resource battles in the soil. Keep them away from your cauliflower beds if you want good heads to harvest.
I learned about bad cauliflower companions the hard way in my third year of growing this crop. I planted tomatoes right next to my cauliflower thinking the tall plants would shade the heat-sensitive heads. Instead both crops suffered and neither produced well that season.
My garden club friend made cauliflower planting mistakes when she put peppers in the next row over. Her heads came out small and bitter. The peppers took up the nitrogen both crops needed from the ground between them.
Strawberries rank among the worst neighbors for your cauliflower plants. They draw slugs to the garden like a magnet pulls metal. Those slugs will crawl over to your cauliflower and chew holes in the leaves. Damaged leaves mean stressed plants and smaller heads at harvest time.
Other brassicas like broccoli, cabbage, and kale share pests with cauliflower. Cabbage worms attack the whole family with equal force. Plant these crops together and one pest outbreak spreads fast. Keep at least 4 feet between brassica groups or put them in different beds.
Here is a quick list of what not to plant with cauliflower in your garden space. Tomatoes and peppers compete for the same nutrients your plants need. Pole beans grow tall and shade your low-growing heads. Corn sucks nitrogen from the soil at rates that starve nearby crops. Rue gives off chemicals that stop brassica growth cold.
Heavy feeders cause the most common problems you will face with poor companions. Squash, corn, and melons all pull huge amounts of food from the soil. Your cauliflower plants cannot compete and end up with yellow leaves and tiny heads.
The fix is simple once you know which plants clash with your cauliflower. Keep problem crops in beds at least 4 feet away from your brassica section. Better yet, put them on the opposite side of your garden plot with a buffer zone between.
Good companions do exist and can help your cauliflower thrive. Celery repels cabbage moths with its strong scent. Onions and garlic keep many pests away from nearby crops. Beans add nitrogen to the soil but stick to bush types that stay short enough to avoid shading issues.
Spinach and lettuce make great row partners since they need similar cool temps and light water. They fill space between your plants without stealing much food. Dill and mint attract good bugs that eat the pests you want gone from your garden.
Plan your garden layout each spring with these rules in mind. Draw a map showing where each crop will go. Check for conflicts before you plant a single seed. This simple step prevents the headaches that come from bad plant neighbors fighting in your beds all season long.
Read the full article: Growing Cauliflower: 7 Key Tips
