By Carrie Knutson, Horticulture agent

NDSU Extension – Grand Forks County

Sometimes, I run out of space in my garden or have extra transplants after planting the garden. I usually end up planting these extras in my containers. Container gardening is a great way to supplement in-ground or raised bed production. Containers can also serve as the sole production source for those with small spaces or those short on time and labor.

There are many different styles and types of containers, from fabric bags to plastic or clay pots. When gardening in containers, you must match the correct pot type and size with the plants you want to grow.

The larger the plant, the larger the container. For example, lettuce and green onions will work well in containers that are 1 to 2 gallons in size, while tomatoes will need containers at least 5 gallons in size. Whatever container you select, make sure it has drainage holes or make them yourself. Drainage holes should be at least a 1/4 inch in diameter.

Potting soil mixes are best for containers. They hold water and nutrients, and drain excess water easily. They are also light, which makes moving containers around easier. Pure garden soil is heavier and will compact in the containers, causing drainage issues.

Select plants that are bred for small spaces. Some keywords to look for are "dwarf," "compact," "bush,” or "space saver." Make sure the plants you select for the containers have complementary characteristics. Combine root and leaf vegetables in a container, as they have different space needs, or plant cool-season crops like lettuce or spinach with peppers. The greens will be harvested early, allowing space in the container as the pepper grows. Ornamentals can be added to the containers, too. Combining edible and ornamental plants creates containers that please the eye, produce a bountiful harvest and benefit the environment.

Containers will need 8 to 12 hours of sunlight. Flowering and fruiting vegetables will need more than leafy greens. A west or south-facing exposure will provide sunlight, provided structures don't block it. Containers can be moved as the light changes in a site but be sure you can lift them. 

Containers have a limited area for growing roots and will need frequent watering. Check the containers daily for moisture. They will need more water in hot, dry weather. Sometimes, watering twice a day. A slow-release fertilizer can be incorporated at planting, or a water-soluble fertilizer can be used during the growing season. Read and follow the application directions.

Growing vegetables in containers is a great way to add some nutrition to your diet and beauty to your landscape. What vegetables can you add to your containers? Happy gardening!

NDSU Agriculture Communication – May 1, 2025

Source: Carrie Knutson, 701-780-8229, carrie.knutson@ndsu.edu

Editor: Kelli Anderson, 701-231-6136, kelli.c.anderson@ndsu.edu