10 Plants You Should Never Grow Next to Lettuce, According to Gardening Experts

Lettuce growing in garden

Lettuce is a low-maintenance crop that can flourish under the right growing conditions. However, if your lettuce is struggling, it may be because of the plants growing next to it. For example, vegetables that need the same nutrients as lettuce can inhibit the plant’s growth. Additionally, some plants can attract pests and diseases that wreak havoc on lettuce.

Pumpkin

Pumpkin growing pumpkin patch

Pumpkins (Curbita spp.) are vining plants that take over a large area in the garden, while lettuce has the opposite growth habit. “Lettuce tends to have a small-sized habit—it doesn’t spread or have much vigor,” says Isabel Branstrom, product development manager for vegetables at PanAmerican Seed. Vining plants like pumpkins can take space away from lettuce. “They can smother the lettuce plants and prevent them from growing to their full potential—or make it difficult for the gardener to harvest the leafy greens,”

Nasturtiums

Nasturiums
 

Nasturtiums (Tropaeolum spp.) are another vining plant that shouldn’t be planted next to lettuce. “Even though nasturtiums are considered edible flowers, this genus also has the potential to take over a garden space, spread, and smother lettuce plants,” says Branstrom.

Don’t fret if you have nasturtiums near lettuce—it’s not always bad. This flower can attract aphids away from leafy greens—just be sure to cut it back or redirect it if it starts to take over your lettuce.

Cauliflower

closeup of white head of cauliflower growing in garden surrounded by long, wavy green leaves
 

Cauliflower (Brassica oleracea) can deplete the soil of nutrients, which may hinder the health and yield of your lettuce plants. What’s more, cauliflower can attract armyworms and cutworms to your garden, two pests that feed on plant foliage.

Kale

Kale leaves growing in the garden
 

Since kale (Brassica oleracea) is also a leafy green, you might think it pairs well with lettuce. However, according to Todd Breyer, garden chair of Antiques & Garden Show of Nashville, kale comes from the brassica family of plants, and therefore, it adds chemicals to the soil that are not good for lettuce. “The brassicas secrete chemicals that inhibit the germination of lettuce seeds,”.

Celery

close-up of growing celery plantation (leaf vegetables) in the vegetable garden
 

Celery (Apium graveolens) is another plant that shouldn’t be planted next to lettuce. “Celery is said to cause lettuce to bolt and go to seed,” says Breyer, adding that this can change the taste of lettuce.

Pole Beans

Common garden beans growing in a garden
 

Known for their tall height, pole beans (Phaseolus vulgaris) can block the sun from reaching other plants, which can happen when you plant them too close to lettuce. “Lettuce needs full sun, so avoid anything, like pole beans, that grows tall and would shade lettuce,” says Marek Bowers, founder of Bolder Green.

Sunflowers

Close up of sunflowers blooming in a garden
 

Sunflowers (Helianthus annuus) add chemicals to the soil that lettuce can’t handle. “In addition to being tall and thus casting shade on lettuce, sunflowers also release allelopathic chemicals (chemicals that affect germination) that inhibit the growth of many garden plants, including lettuce,”.

Fennel

Fennel growing
 

Fennel (Foeniculum vulgare) also adds allelopathic chemicals to the soil. “You should always avoid things that inhibit the growth of other plants, like fennel,” says Breyer. Since this plant doesn’t play well with others, fennel should always be grown in a pot, away from most other plants.

Cabbage

Cabbage growing in the garden
 

Cabbage (Brassica oleracea) is another leafy green that lettuce doesn’t grow well next to. A member of the brassica family, cabbage competes with lettuce for essential nutrients and secretes chemicals that inhibit its growth.

Broccoli

Broccoli growing in garden close up view
 

To help form its flowers, broccoli (Brassica oleracea) pulls plenty of nutrients from the soil, thus depriving lettuce of things it needs to grow. Broccoli is also a member of the brassica family, so it’s best to keep it away from your lettuce.

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