Growing Vegetables in Containers

The first step in growing vegetables in pots is choosing the right container size. The ideal size depends on the type of vegetable you are growing. With plants like bush beans or leaf lettuce, for example, you can get by with a relatively small (10-inch) pot, while an eggplant or bush-type tomato needs a larger (18-inch) pot. Follow these guidelines.

(Numbers in parentheses refer to the number of plants you want to end up with in the pot, whether you plant seeds or seedlings.)

Plant a 10-inch pot with:
leaf lettuce (1)
Swiss chard (1)
bush beans (1)
French (round) carrots (11 to 12)
turnips (4)

Plant a 14-inch pot with:
dwarf sweet corn (6 to 7)
cabbage (1)
collards (1)
carrots (9 to 10)
edamame (2)
peas (4)
leaf lettuce (3 to 4)
spinach (3 to 4)
arugula (3)

Plant an 18-inch (or larger) pot with:
pole beans on trellis (3 to 6, depending on trellis type)
broccoli (1)
cauliflower (1)
eggplant (1)
pepper (1)
determinate tomato and support (1)
any kind of green, leafy vegetables (varies; see plant tag or seed packet for spacing guidelines)

Plant a 24-inch (or larger) pot with:
indeterminate tomato and cage (1)
cucumber (1)
summer squash (1)
artichoke (1)

No matter what size pot you use for growing vegetables, it must have drainage holes to allow excess water to drain away. Otherwise, your plants will most likely drown from overwatering.

To grow a successful container vegetable garden, start with great soil—not soil from your yard, but what’s known as a potting mix. These mixes, like Miracle-Gro® Potting Soil, contain the right blend of materials like coir, peat moss and/or compost to create an ideal growing environment for roots inside a pot. Potting mixes don’t compact, but instead provide good drainage and air flow. Another great option is Miracle-Gro® Moisture Control Potting Mix, which helps protect plants against over- and under-watering. If you're planning to re-use last year's potting mix, you'll want to work a little rejuvenation magic first. Add a layer of Miracle-Gro® Refresh 1™ Soil Revitalizer per the label directions to restore nutrition and other soil components that your plants need to grow their best.

Place your container vegetable garden in a spot that receives at least six hours of sun daily, wherever that may be. (Know that pots placed on pavement, though, tend to heat up and need extra water.) Growing vegetables in pots allows you to fudge the growing season by placing pots in an area with a micro-climate. For instance, lining pots along a south-facing wall in early spring warms soil quickly so you can plant sooner. In autumn, a south- or west-facing wall retains heat and can help extend the growing season as frost threatens.

Pots dry out much faster than in-ground gardens, which is why container gardening success hinges largely on watering. As vegetables grow and roots fill the soil, plants need more water to stay healthy and yield a harvest. You'll want to check soil daily, and water whenever the top inch becomes dry. Another option is to install a drip irrigation system (sold in simple-to-assemble kits online and at home improvement stores) that will do the watering work for you.