9 Vegetables You Should Never Grow in Pots and Containers, According to Experts

Pumpkins

It's tempting to grow your own pumpkin patch in a container, but these vegetables need a lot of water and nutrients.

"Their root systems will quickly outgrow most containers and may result in a stunted plant that doesn’t produce well," says Brooke Edmunds, a professor and horticulturist at Oregon State University Extension.

According to Laura Irish-Hanson, horticulture educator at the University of Minnesota Extension, these plants can grow to be 10 to 15 feet wide, so a container will need a lot of fertilization in order for them to bear fruit.

Corn

Most varieties of corn grow 5 feet tall or more and can be top-heavy, says Edmunds—so if these plants are grown in a container, then a small breeze could topple them.

Corn also produces the best ears when grown in a large patch. "This is because it is wind-pollinated, so you need many plants to pass pollen to each other so the ear fills out with kernels," she says.

Carrots

Long-rooted varieties of carrots, like CandySnax, Long Imperator, King Midas, and others, may get too big for containers, says Edmunds.

"The taproots may quickly outgrow the depth of the container and become distorted," she says. If you're determined, though, you can find some shorter hybrid varieties, like Short n’ Sweet, Parisian, or Bambino. Just make sure to check the seed packet or catalog for shorter varieties.

Brassicas

Brassicas like broccoli and cauliflower grow to be large plants with large root systems, which may be troublesome to manage, depending on your container size.

They're also cool-season crops, says Edmunds, which means they need cold weather to thrive—but this can be tricky to control. "Soil in containers is subject to more swings in temperature than in-ground beds, which can lead to poor growth of broccoli and cauliflower," she adds.

For the best results, Edmunds recommends growing these plants in the ground or a raised bed, as that insulates the plants better and allows the root system to expand.

Artichokes

An artichoke may seem small enough, but this plant can grow to be 5 to 6 feet across, depending on the cultivar.

"In many regions, artichokes are perennials, and they quickly outgrow their containers," says Edmunds. "If grown in a container, the plants will struggle to thrive and will likely produce few flowers."

Garlic

Garlic is another plant that may grow well in a container, but it can be susceptible to extreme swings in temperature, depending on where you live.

"Garlic should be planted in the ground in the fall to allow the roots to establish," says Irish-Hanson. "In a container, you have a much greater chance that the soil will freeze and rot out the cloves."

Indeterminate Tomatoes

Some tomato cultivars are determinates, which means that their growth stops with each flowering cluster, preventing the vine from getting too long. These tomatoes may only bloom once or twice a season.

However, indeterminate tomatoes keep growing and will quickly outpace the size of the container. You may get more fruit from the plant, but you're unlikely to keep up with its size, watering, or nutrient demands.

Asparagus

Asparagus can grow to be about 5 feet tall, and, like corn, it needs lots of space in order to develop.

"You're harvesting the spears as they come up," says Hillock. "So you really need lots of room for the base. They'd be a little too cramped in a typical container."

Celery

You can technically plant celery in a container, but it's difficult to grow, as it needs lots of moisture, sunlight, and nutrients, says Hillock. For many gardeners, doting on the plant for four months straight could be a challenge.