Poor soil? Low sun exposure? No garden? You can still grow vegetables! Almost any vegetable can be grown in a container, but varieties that work the best are “compact” or “bush” plants: plants that have a confined growth habit. Here are steps to grow four popular vegetables in containers.
A few general tips: If the container ultimately will be too heavy to move, consider placing a wheeled platform underneath for maneuverability. Potting soil mix should be used, not regular garden soil. Finally, you will likely need to water your container plant every day, maybe twice on particularly hot days. An inch of mulch can be placed on top of the soil to help retain moisture.
The container size you will need depends on the tomato type. Standard tomato plants should be planted in a 24”-deep container, while dwarfs should be planted in 12”-deep containers. Fill a 24” container with 7 gallons of potting soil mix or a 12” container with 3.5 gallons of potting soil. Bury either a tomato transplant or seed about 40% deeper than you would plant in a garden, making sure to cover the stem with soil. Incorporate a tomato cage for support.
Fertilizing your tomato plant is essential. Use both a timed-release and water soluble fertilizer. Include the time-released fertilizer when planting, mixing it right into the potting soil. Measure ½ tablespoon to each gallon of soil mix. Add water soluable fertilizer once the plant begins to produce to enrich the potting soil. Slightly reduce the fertilizer’s labeled strength and add every 1-2 weeks.
Any variety of pepper can successfully grow in a container 16” deep. Fill with 5.5 gallons of potting soil and mix in 3 tablespoons of a time-based fertilizer such as Osmocote 14-14-14. Plant peppers the same depth as you would in a garden. Add a trellis to support peppers as they grow.
Peppers will also need to be fertilized once they begin to produce. Use a water soluable fertilizer such as Miracle Gro 15-30-15 every week or two. If you want a large harvest, you could try your luck with a 10-50-10 fertilizer that has a high phosphorous content. Add conservatively and give the plants a few hours of shade to retain moisture.
Popular Fordhook lima beans grow nicely in a 12” wide, 8-10”-deep container. Fill this container with 2.5 gallons of potting soil, adding 2.5 tablespoons of a balanced, slow-release fertilizer. When lima beans appear, add a water soluable fertilizer such as Peters 20-20-20. Use stakes to form a supportive tepee in the container, which can also be used as protection from the sun by draping fabric over the top.
All container plants, including lima beans, need extra watering attention since potting soil doesn’t retain moisture as well as garden soil. Therefore, water every day—more if you use a porous clay container. Drip irrigation works well. Check often for signs of disease and pest infestation.
All varieties of spinach are compact plants, so choose your favorite type. The ideal size container for spinach plants is 4-6” deep; fill with 1-2 pints of potting soil mix and ¼ tablespoon of a balanced fertilizer. Water daily and move the plant to a shady spot for several hours so the soil can absorb moisture.
Once the plant begins to produce, add a water soluable fertilizer every 1-2 weeks. Container plants actually require a bit more care than in-ground plants, but don’t let that scare you. Simply keep hydrated, support as necessary, check often for distress, and fertilize throughout the growing season.
Once you harvest, discard the container’s contents, as they are no longer useful: the nutrients are gone and you don’t want to encourage the potential spread of disease.
For more information on container gardening, check out this Fact Sheet from Ohio State University.