Spurred by the heightened awareness of healthy foods and the fast-spreading locavore movement, vegetable gardening has become a national craze gripping the country with a fervor not seen since the days of WW II and the cultivation of victory gardens. Middle school kids are raising vegetables for their cafeterias. Apartment dwellers are growing vegetables in community plots. And some very green gardeners are even cultivating crops on green roofs. But what if you have no access to a plot of land or your plot of land is so shady only moss can thrive, can you share in this booming pastime? Absolutely you can. Sow and grow your vegetables in containers. Raising crops in pots on patios, decks and apartment rooftops has some advantages over in-ground cultivation. For one thing, pots are portable and if need be can be moved around to follow the sun’s path; remember, vegetable plants need at least six hours of full sun. Also the soil in pots warms up more quickly than soil in the ground, effectively extending the growing season. Container gardening eliminates the threat of pathogens such as fusarium and verticillium wilts, two soil-borne fungi that clog plant tissue restricting water intake eventually killing the plants. And growing crops in pots deters vegetarian critters such as voles and slugs from feasting on food meant for your family.
If you want to try growing vegetables in containers you will need a big pot at least 12 inches deep and a bag of sterile potting soil that contains perlite. The pot must have drainage holes and should be made of plastic, fiberglass or glazed terra cotta – glazed on the inside, that is. Plain terra cotta pots, although very attractive, wick away water quickly forcing the gardener to water the plants once, maybe even twice a day. To minimize the stress on both you and the plants here’s a suggestion: mix into the potting soil a timed release vegetable fertilizer such as Osmacote and soil moist polymer crystals like Soil Moist which retain water and release it as the soil dries out. These two additions to the soil ensure that your plants get fed on a regular basis and reduce the frequency of watering. However, soil in pots dries out more rapidly than soil in the ground, so be vigilant. Now that your container is ready to plant it’s time to talk about the vegetables.
Tops on almost everybody’s list are tomatoes. For those unfamiliar with growing tomatoes the plants can be either determinant or indeterminant. Determinant tomatoes reach a certain height and produce their fruit all at once. These are often touted as the only tomatoes that do well in a pot. Not so. An indeterminant tomato which continues to grow during the heat of the summer producing fruit throughout the season can thrive in a large pot, but it must be supported; either a stake or a cage will do the trick. Most of the highly desirable heirloom tomatoes are indeterminant, but their flavor justifies the extra effort and cost. Some seed companies have developed dwarf heirloom tomatoes specifically for containers so if your growing season is long or you can start the seed indoors you are fortunate since the dwarf plants are not readily available in nurseries or garden centers. For a large rich heirloom slicing tomato you can’t beat “Mortgage Lifter” or “Brandywine”. If you favor a smaller tomato the tasty 2 inch heirloom “Stupice” from the Czech Republic gets rave reviews. Once you have selected your tomato plants mix some crushed oyster shells in with the soil to add additional calcium and help prevent blossom end rot. Then if possible position the pot near flowers or herbs to attract bees and encourage pollination.
Other vegetable candidates for container gardening include Swiss chard, cucumbers, peppers, kale, summer squash, lettuce and green beans. When selecting beans you have a choice, pole beans or bush beans. Bush beans are better behaved but like determinant tomatoes they produce a single crop all at once. Pole beans must be staked or restrained in cages but they will reward this extra effort with several bursts of beans during the summer if you harvest them often when the pods are young; once the pods mature the plants stop producing. Two good selections of pole beans for your containers are “Bean Beananza”, a dwarf French bean, and the reliable “Kentucky Wonder”.
In contrast to bush beans, bush cucumbers win out over the vining varieties simply because they are more compact, less unruly. Two of the better behaved are the prolific producers “Bush Champion” and “Spacemaster”. Cucumbers thrive in the heat of summer but rebel against a full day of sun. Too much sun turns the fruit bitter, so try to position your cucumber plants where they will get dappled sun for part of the day.
With a bow to the current food fad, kale is a natural for container gardening especially “Tuscan Baby Leaf”. This variety is a ‘cut and come again’ type that is harvested when it reaches four to five inches tall ensuring a summer’s worth of healthy eating.
Expanding on the theme of leafy green vegetables, Swiss chard is another container candidate, but since it is tap-rooted select your deepest pot for planting. A flashy variety “Bright Lights” relishes frequent cutting which encourages new growth, and since it is a cool weather crop, unhappy when the temperature rises above 80 degrees, plant as soon as the soil can be worked. Lettuce too flourishes in cool weather; it is said in the Northeast that lettuce can be planted on St. Patrick’s Day, so if you live in USDA Zones 5 or 6 sow some lettuce seeds before you tuck in to the corned beef and cabbage. One of the leafy types, “Salad Bowl”, is especially suited to container gardening, and once again pick the leaves when they are young. If you prefer a head lettuce you can’t go wrong with the organic Bibb “Patty’s Choice”.
The final selections of vegetables for your containers are the heat-loving trio, eggplant, summer squash and peppers. All types of peppers from sweet bell to habaneros grow well in pots, but peppers are tropical plants so wait to sow the seed until the last frost has passed. As for eggplant two choice varieties for container growing are “Slim Jim” which grows to about 3 feet, producing 4-5 inch fruit and “Black Beauty” whose shape and size resemble the eggplant commonly found in supermarkets. Both are sweet, never bitter, and both must be staked because of the weight of the fruit. Summer squash, the last in the trio, also needs support. The mantra to reaping a bountiful harvest from containers is “grow vertically”. A fine yellow squash is “Cosmos Hybrid”, and just for fun try planting round zucchini instead of the elongated variety. It’s fast growing; the fruit is ready to eat just 7 days after flowering so pick when the globes reach 3-4 inches in diameter. Once you have harvested your eggplant, peppers and squash, saute some onions and garlic, toss in the trio, and you have the makings of a delicious ratatouille, a yummy tribute to summer.
Although this discussion focused on raising vegetables in containers from seed, many gardeners can buy established plants from a nearby nursery or garden center. They’re in luck because many of the heat-loving vegetables – tomatoes, eggplant, summer squash, peppers, and cucumbers – can take up to three months to reach maturity, so let the nursery do the work and start the plants for you. If you can’t count yourself among the lucky ones try to start your seed indoors 6-8 weeks before the last frost, and once the weather has warmed up harden the plants off by moving them outdoors during the day and back in at night before transplanting them to their containers.
So even though you may be short on space you can join the middle school kids, the apartment dwellers and roof top gardeners by raising vegetables in containers, a highly rewarding and healthy hobby. Enjoy the bounty.
Some Seed Sources