AMES, Iowa – A traditional home garden is a popular way to grow vegetables, but it’s far from the only way. Growing vegetable plants in containers can also produce a bountiful crop, although care must be taken to ensure meaningful growth.
ISU Extension and Outreach horticulturists can help answer your questions about how to best handle container growing of vegetables. To have additional questions answered, contact the ISU Hortline at 515-294-3108 or firstname.lastname@example.org.
Plants grown in containers require a well-drained growing medium. Garden soil alone is not a good growing medium. Garden soil compacts when placed in a container, resulting in poor water drainage and aeration. Soil also pulls away from the inside of the container when it dries, making it difficult to properly water plants. A homemade potting mix can be prepared using equal amounts (volumes) of garden soil, sphagnum peat moss, and perlite.
A commercial potting mix is often the best choice when gardening in containers. The quality of commercial potting mixes varies considerably. Poor quality potting mixes are often inexpensive, black, heavy, and don’t drain well. High quality commercial potting mixes are lightweight, well-drained, free of plant disease organisms and weed seeds, retain moisture and nutrients well, and don’t readily compact. Commercial potting mixes can be purchased at garden centers and many other retailers.
Containers may be plastic, clay, ceramic or wood. The container must be able hold an adequate amount of potting soil and have drainage holes in the bottom. Drill drainage holes in plastic and wooden containers, if no drainage holes are provided.
In regards to size, several leaf lettuce or spinach plants can be grown in a one gallon container. A single pepper or eggplant can be grown in a two gallon container, while a four gallon container would be necessary for a single tomato plant.
Determinate tomato cultivars are best suited to growing in containers. Determinate tomatoes are small, compact plants. They grow to a certain height, then flower and set all their fruit within a short period of time. Indeterminate tomatoes are large, sprawling plants which get too large for most containers.
Suggested tomato cultivars for containers include ‘Bush Early Girl,’ ‘Better Bush,’ ‘Celebrity,’ ‘Patio Hybrid,’ ‘Patio Princess,’ Sweet ‘n Neat Scarlet’ (cherry), and ‘Sweet Zen’ (grape).
Most cucumbers, melons, and squashes are not well suited to containers as they are large, sprawling plants. However, bush-type cucumbers and summer squash can be grown in containers. Bush-type cucumber cultivars suitable for containers include ‘Spacemaster,’ ‘Salad Bush,’ ‘Pickle Bush,’ and ‘Patio Snacker.’ Bush-type summer squash, such as ‘Zucchini Elite,’ ‘Gold Rush,’ ‘Sunburst,’ and ‘Patio Star,’ can also be grown in containers.