Whether you want to grow a few herbs on the kitchen windowsill or plant a vegetable garden in half barrels and large planters on a sun porch, growing edibles in containers is a smart way to keep fresh food close at hand. And, planting and growing a vegetable garden makes a great project to engage the little ones. Remember, size matters -- container size that is -- when growing a vegetable garden indoors.
Types of Containers
You can buy classic terra cotta containers, or grow your indoor vegetable garden in a few buckets and old apple crates. Found containers that make good planters include coffee cans, 5-gallon buckets, old colanders and half wine barrels. Size is important, but drainage is equally important. Make sure the planter has at least one drain hole in the bottom. If you are using a wood or plastic container, drill at least one, preferably two to three, 1/2- to 1-inch-diameter holes in the bottom. For metal coffee cans, punch holes through the bottom with a hammer and an old screwdriver.
Dimensions and Soil Capacity
There are two ways to measure a container: using the volume or the height and diameter. When using containers you already have, it helps to know the approximate dimensions and volume. For example, a 4-inch pot has an approximate volume 1 quart. A 1-gallon-planter will have a diameter of about 8 inches, while a 2-gallon pot will be closer to 10 inches. If you're looking for a 5-gallon planter, select one that's about 14 inches in diameter. Larger pots, like half barrels, commonly have a 24- to 30-inch diameter and hold 30 to 55 gallons of potting mix.
Measuring Soil Capacity
Keep in mind that volume varies by both the height and diameter of the planter. If you are not sure of the soil capacity, especially when when using a wood crate or an oddly shaped planter, measure the soil volume to get an idea of what to grow. Using a 1-gallon bucket for large planters, or a cup measure for small pots, fill the planter with soil. Count how many go in to determine the volume.
Single Vegetable Container Sizes
Cherry tomatoes (Lycopersicon esculentum), eggplants (Solanum melongena) and peppers (Capsicum annuum) need a 2-gallon container, while full-size tomatoes require a 4- to 5-gallon container. These vegetable garden favorites are frost-tender perennials commonly grown as warm-season annuals. Tomatoes grow in U.S. Department of Agriculture plant hardiness zones 10 through 11, while peppers will grow as perennials in USDA zones 9 through 11 and eggplants in USDA zones 9 through 12.
One-gallon containers make good planters for two or three parsley plants (Petroselinum crispum) or two or three lettuce plants (Lactuca sativa), both annuals that will grow during the warm season in all climates. Half-gallon planters work well for herbs, like oregano (Origanum vulgare) and sage (Salvia officinalis), both hardy in USDA zones 4 through 8; and thyme (Thymus vulgaris) which grows in USDA zones 5 through 9. To grow the annual herb cilantro (Coriandrum sativum), a shallow 12-inch-diameter, 6-inch-deep pot works well.
Mixing and Matching
You can combine different types of vegetables in a large pot. Try planting a herb container garden to keep all your culinary flavors close at hand. Grow a tomato plant in a 5-gallon container and plant three or four annual basil plants (Ocimum basilicum) around the edge of the planter. If you have the space indoors, plant a 30-gallon, 24- to 30-inch half barrel with a mixture of annual salad greens, like lettuce, arugula (Eruca sativa), endive (Cichorium endivia) and mizuna (Brassica rapa var japonica), also called potherb mustard, to the mix.