Tomatoes

Tomatoes and broccoli have conflicting soil requirements, says Ankit K. Singh, assistant professor of sustainable agriculture at the University of Maine. Tomatoes prefer slightly acidic soil, while broccoli thrives in neutral to slightly alkaline soil.

Additionally, both crops are heavy feeders that will compete for calcium and nitrogen if grown together, leading to nutrient deficiencies in both crops. Tomatoes can also shade broccoli, reducing the amount of sunlight it needs to develop properly, says Singh.

Strawberries

Strawberries are a beloved summer fruit but keep them away from your broccoli plants. Singh notes that strawberries can spread aggressively, crowding out broccoli and competing for nutrients. “Strawberries release compounds into the soil that can inhibit broccoli growth, stunting its development,” he says. Additionally, strawberries attract pests like aphids and slugs, which also feed on broccoli, increasing the risk of infestations.

Beans

Pole and bush beans fix nitrogen in the soil, which benefits other plants like leafy greens but not broccoli. Growing these plants together can lead to excessive leafy growth in broccoli, reducing the development of the edible heads, says Singh. Pole beans also climb and spread, which can shade broccoli, limiting sunlight exposure.

Peppers

In this case, opposites do not attract. “Peppers require warmer temperatures, while broccoli thrives in cooler conditions, making them incompatible in terms of growing seasons,” says Singh.

Both crops are heavy feeders, leading to competition for nutrients, especially phosphorus and potassium. Another reason these plants aren’t compatible? “Peppers can be susceptible to similar pests, increasing the risk of cross-infestation,” Singh says.

Brassicas

Don’t grow broccoli alongside other members of the brassica family, such as cauliflower, cabbage, Brussels sprouts, and kale. These plants compete for the same nutrients, which can deplete the soil and inhibit growth.

Because they’re from the same family, these plants are susceptible to the same pests and diseases, including cabbage worms and aphids. Unfortunately, growing these crops together raises the risk of disease outbreaks, making pest control more challenging, says Singh.

Pumpkin

Growing pumpkins in the same row or raised bed as broccoli may have negative results for your crops. “Pumpkin is a heavy feeder of soil nutrients and has sprawling vines and leaves that will most likely out-compete your broccoli crop in every way,” says Eric Nieusma, regenerative farmer at Maine Hill farm.

Sunflowers

Planting sunflowers near broccoli is generally not advised for several reasons. First, sunflowers can grow two to five times taller than broccoli, potentially blocking sunlight. Additionally, sunflowers are heavy feeders and require many of the same nutrients as broccoli, which can result in poor growth for both crops.

Moreover, sunflowers attract birds that may inadvertently carry aphids, a common pest that affects broccoli. For these reasons, it is best to plant sunflowers along a border, at the edge of the garden, or in their own row on the north or west side of the garden.