Broccoli may be a vegetable that you either love or hate, but once you grow it, you’ll most likely love it. It’s an excellent crop for the cool season that can handle a little bit of light shade. They are also big, beautiful plants that can produce for several weeks. Try growing the “Romanesco” type to add interest to your garden.
We’ll cover the best broccoli companion plants, and also what not to grow with broccoli.
5 Best Broccoli Companion Plants
- Sweet Alyssum
An explanation of why these plants grow well with broccoli is below.
Planting & Avoiding Pests
There are two ways to plant broccoli companion plants. The first one is solely intended to save space. Broccoli can take up a significant amount of space in the garden and do so for a long time.
To make up for this, you can plant fast-growing plants like leaf lettuce, beets, and radishes near broccoli.
Avoiding Pests Using Companion Plants For Broccoli
Some companions will help eliminate aphids and cabbage worms, the two biggest problems for brassicas in the spring.
If you plant a carpet of sweet alyssum under your broccoli, hoverflies will be drawn to it, and the hoverfly larvae will eat the aphids.
You can plant calendula as a trap crop to catch any aphids that the hoverflies don’t get.
Aphids like calendula, and many of them will pick that instead of your broccoli.
You can pick cabbage worms off your plants by hand or use Bt to get rid of them. However, if you plant dill near them, parasitic wasps will come and lay eggs under the caterpillars’ skin, and the larvae will then eat the caterpillars from the inside out.
What Not To Plant With Broccoli: 4 Plants To Avoid
- Beans: You’ll want to avoid planting broccoli with beans because it could create too much nitrogen in the soil. Nitrogen is good, but like all good things, too much can make it a good thing bad.
- Nightshade: While this is not always the case, it’s best to avoid nightshades such as peppers, tomatoes, and eggplants. These can have negative effects on broccoli.
- Strawberries: The problem with strawberries and broccoli is that strawberries can deplete broccoli nutrients. This is due to strawberries being considered a “heavy feeder.” Then, when depleted, it could stunt broccolis’ growth.
- Cauliflower and Cabbage: You’ll want to avoid these plants with broccoli because they’re also a part of the brassica family. Which means they will compete for nutrients and also attract more pests.
Planting Broccoli: When, Where & Spacing
When you can plant broccoli will depend on how harsh your winters are. If you have mild or no frosts during the winter, you can plant broccoli in late summer or early fall, and it will grow all the way through the winter.
You must plant your broccoli in the spring if your winters are cold.
No matter where you live, you will either want to start with transplants or grow plants from seeds inside. It will most likely be too hot to start seeds outside in late summer or early fall.
Broccoli seeds can only grow in soil that is below 70°F (21°C). You’ll want to plant early for spring sowing because broccoli can take up garden space for about six months.
This means it can take up space you want to use for warm-season crops. So, for example, you can start broccoli seeds indoors six weeks before your last frost date.
Once your seedlings or transplants are ready to go into the garden (they can handle cold so that you can put them out two weeks before your last frost date), they need at least four to five hours of direct sun and ideally six to eight, but they can also handle some shade.
Plant them 15 to 18 inches (38 to 46 cm) apart in rich, well-draining soil and make sure they stay moist.
Growing & Harvesting
Even though you can eat broccoli leaves, most people grow them for their edible flower buds. The first floret will grow from the center of the top of the plant.
It will be small initially but will get much bigger as it grows. You’ll know it’s ready to harvest when the tight flowers look like they’re just starting to loosen up, but you have to harvest them before they bloom.
Next, use a knife or clippers to cut the stalk below, where it starts to split into different segments.
If you look down the main stalk where the leaves grow from, you will probably see little florets starting to grow. These will become your second crop.
They won’t get nearly as big as the main floret, but they will keep growing as long as you keep picking them.
Are carrots and broccoli companion plants?
Unfortunately, no, they are not. Avoid planting carrots next to broccoli. If grown together, a calcium deficiency (ctahr.hawaii.edu; PDF) could develop in the soil and plants.
Can cabbage and broccoli be planted together?
No, you should not grow broccoli and cabbage together. They will compete for nutrients since they are both a part of the brassica family (oecd-ilibrary.org; PDF) and attract a greater number of pests.
Can broccoli and cauliflower be planted together?
No, broccoli and cauliflower should not be planted together for the same reasons as the above answer about cabbage. They compete and attract more pests.
Davin is a jack-of-all-trades but has professional training and experience in various home and garden subjects. He leans on other experts when needed and edits and fact-checks all articles.