7 Vegetables You Should Avoid Planting Together in Your Garden Bed

1. Potatoes and Tomatoes

Potatoes and tomatoes are both part of the nightshade family, and planting them together can significantly affect their growth patterns if placed in the same area. According to Ruby Dessiatoun, Senior Farmer at Love & Carrots, 'Potatoes are typically planted early in the spring, with their disease risk peaking early in the summer, just when tomatoes are beginning their growth phase.' She continues, 'When you plant potatoes and tomatoes close to each other, it raises the likelihood of tomatoes contracting potato diseases, and by the time you notice, it's too late to replant.'

2. Garlic or Onions and Legumes

Growing garlic or onions alongside peas and beans in the same garden bed can seriously jeopardize the health and growth of your legumes. Ruby Dessiatoun explains, 'Alliums, like garlic and onions, release sulfur compounds into the soil,' which can 'hinder legumes such as peas and beans,' preventing them from reaching their full growth potential.

3. Garlic and Onions

When it comes to garlic and onions, Dessiatoun points out, 'They are both heavy nitrogen consumers.' She warns, 'If you're not consistently fertilizing them during planting, having both of these nitrogen-hungry plants side by side can rapidly deplete the soil of essential nutrients, causing them to compete for resources.'

4. Broccoli and Tomatoes

Broccoli is often planted in early spring, which aligns with the time you’d typically plant your tomatoes. However, Ruby Dessiatoun advises against planting them together. 'There is a common belief that tomatoes can be stunted when planted near broccoli or other cruciferous vegetables,' she says. 'This may be due to the accumulation of sulfur compounds in the soil.'

5. Oregano and Squash

Ruby Dessiatoun explains, 'Oregano can easily be overwhelmed by the fast-growing, sprawling squash plants.' Moreover, they have very different water needs, making it tough to grow them in the same bed. 'Oregano is a perennial that requires minimal water once it’s established,' she says. 'On the other hand, squash is an annual that has large leaves, tends to dry out quickly, and demands much more water than oregano can handle.'

6. Potatoes and Cucumbers, Squash, or Melons

“Potatoes are planted early in the season and are well-established by the time cucumbers, squash, and melons are ready to go into the ground,” explains Ruby Dessiatoun. “As the plants begin to wither toward the end of their life cycle, they become more vulnerable to fungal diseases like Alternaria leaf spot, which can spread from the potatoes to the newly-planted cucurbits.”

7. Fennel and Tomatoes

Fennel isn't an ideal companion for tomato plants due to the chemicals it releases, which can stunt the growth of neighboring plants. In fact, fennel's compounds can negatively impact a variety of plants. Ruby Dessiatoun adds, 'Fennel should also be kept away from cruciferous vegetables such as broccoli and cabbage.'

How to Care for Your Vegetables

Sunlight

To make the most of your vegetable garden, it's essential to provide proper care, starting with the right amount of sunlight. Carly Mercer, Vice President of Love & Carrots, advises, 'For optimal growth, most vegetable plants need at least 6-8 hours of sunlight each day.'

“Crops that bear fruit, like tomatoes, squash, and eggplants, thrive with closer to 8 hours of sunlight, and the same goes for root vegetables like carrots and beets. Herbs and leafy greens, on the other hand, can do well with a bit less, around 5-6 hours of sunlight,” explains Mercer.

Fertilizer

The timing of your fertilization is just as crucial. Mercer recommends, 'In the spring, use a granular fertilizer that’s high in nitrogen, and switch to a balanced granular fertilizer mid-summer to help promote fruit production.'

Soil

Mercer recommends well-draining soil for your garden and advises that perennial herbs like rosemary, sage, oregano, thyme, and chives should be grown separately from your vegetable beds. 'We suggest using raised beds for vegetables because they give you better control over soil composition and drainage, are easier to maintain and keep weed-free, and provide a deep base for plant roots,' she says.

Water

When it comes to watering, Mercer suggests a schedule of watering every other day in spring. However, during prolonged summer droughts, watering up to twice a day may be necessary. 'The soil in your vegetable beds should be as damp as a wrung-out sponge,' Mercer explains. 'We recommend using drip irrigation with automated timers, which efficiently delivers water directly to plant roots.'