CORVALLIS, Ore. – Many vegetables grow well in containers located on a patio, porch, balcony or windowsill, so don't let lack of yard space keep you from gardening this spring and summer.
Limited garden space precludes being able to grow some of the larger vegetables, according to Brooke Edmunds, Oregon State University Extension Service horticulturist. For instance, growing corn on a balcony may not be practical. But a wide variety of crops can be planted, including lettuce, herbs, tomatoes, peppers, eggplant, carrots, beans, squash, radishes, kale, chard and spinach.
There are some dwarf and miniature varieties, such as Thumbelina carrots or other baby vegetables that work particularly well in small confines. Vine crops can be put in hanging baskets or grown in oak barrels or large pots and trained vertically on trellises, stakes or railings.
The amount of sunlight available will affect your choice of crops, Edmunds said. Root and leaf crops (beets, turnips, lettuce, cabbage, mustard greens) can tolerate light shade. But vegetables grown for their fruits, including tomatoes, green beans and peppers must have from six to eight hours of direct sunlight each day. The more sun the better.
Almost any type of container can be used, from traditional pots to bushel baskets, metal drums, gallon cans, fabric grow bags, plastic tubs, wooden boxes and well-rinsed cut-off bleach jugs. Ten-inch pots are good for green onions, parsley and herbs. For plants with larger root systems, such as tomatoes, peppers and eggplant, five-gallon containers are best.
No matter what container type is used, adequate drainage is a must, Edmunds cautions. Drill drain holes along the side about 1/2 inch from the bottom and make sure the soil drains well. It also helps to elevate the pot with bricks or boards, off the surface of your patio or pot saucer.
Good soil really helps. Use a packaged potting soil or composted soil available at local garden centers. These purchased potting soils make for excellent container gardening because they are lightweight, sterile and drain well. Avoid topsoil or garden soil; they can be heavy and drain poorly. Same thing with planting mix.
As in bigger gardens, container grown vegetables can be grown from transplants, or they can be planted as seeds. Pre-moisten the soil by adding water and mixing with your hands or small trowel (rule of thumb is that you don’t want to be able to squeeze any water from it). Smooth out the soil surface and then plant vegetable seeds according to the instructions on the seed package, Edmunds said. After planting, gently water the soil, taking care not to wash out the seeds.
Vegetables grown in containers need regular fertilization. A soluble, all-purpose fertilizer that can be mixed in water is the easiest type to use with container plants. Fertilize every three to four days with a solution that is half the strength of the recommended mixing ratio.
Dry fertilizers sprinkled on top of the soil offer a second-best alternative. If you use them, fertilize every three weeks. Organic materials including compost, animal manures, blood meal or rock phosphate and greensand can be used for fertilizer as well.
Religious regular watering is also essential, Edmunds said. The soil in containers can dry out quickly, especially on a concrete patio in full sun. Daily watering is not unusual, but don't let the soil become soggy or have water standing on top of it. Water when the soil feels dry and until it runs out the drain holes. After spring and early summer crops are harvested, the containers can be replanted with late summer and fall vegetables.
For more information on container gardening and other gardening basics, view OSU Extension's publication Growing Your Own.
About the OSU Extension Service: The Oregon State University Extension Service shares research-based knowledge with people and communities in Oregon’s 36 counties. OSU Extension addresses issues that matter to urban and rural Oregonians. OSU Extension’s partnerships and programs contribute to a healthy, prosperous and sustainable future for Oregon.