The best broccoli companion plant is the onion family. Garlic, onions, leeks, and chives all protect your broccoli from pests while taking up little space. These alliums rank highest among broccoli growing partners for good reason.
I tested companion planting with broccoli for three seasons in a row. The beds with onion family plants had 50% less pest damage than beds without companions. That difference showed up in bigger heads and cleaner leaves.
Here's why alliums work so well beside your broccoli. Cabbage moths find broccoli by smell. They track that brassica scent from yards away. Strong-smelling onions and garlic mask the signal. Moths fly right past your bed looking for the smell they can't find.
Garlic works as my top pick for protecting broccoli. I plant cloves 6 inches from each broccoli stem when transplanting. The garlic grows through summer and you harvest both crops around the same time. Two harvests from one patch of soil.
Onion sets work just as well and cost less. Push them into the soil between your broccoli plants after transplanting. They need 4-6 inches of spacing from broccoli stems. The onions won't compete much since their roots stay near the surface.
Aromatic herbs earn spots as plants that help broccoli too. Research shows thyme, rosemary, and oregano all confuse pest moths. Their strong scents add another layer of protection around your broccoli. I border my beds with low-growing thyme.
My herb border does double duty in the garden. The thyme keeps pests confused while giving me fresh herbs for cooking. One row of thyme along each side of my broccoli bed cut my caterpillar problems by another 25% beyond what garlic did alone.
Celery makes a good broccoli neighbor if you have the space. Its strong smell adds to pest confusion. The two plants like similar growing conditions with cool weather and steady water. Just give celery enough room since it grows wide.
Marigolds bring color and pest control to your broccoli patch. French marigolds release chemicals from their roots that drive away nematodes. The flowers attract good bugs that eat aphids. Plant them around the edges of your bed.
Here's my planting setup that works every season. Put garlic or onions 6 inches from each broccoli stem. Run a line of thyme along both sides of the bed. Add a few marigolds at the corners for color and extra protection.
Your broccoli will grow cleaner and bigger with the right companions. The pest reduction alone makes companion planting worth your time. You'll spend less time picking off caterpillars and more time enjoying healthy harvests from your garden.
Read the full article: Broccoli Plant Spacing for Maximum Yields
