The Contained Vegetable Garden

Eliminate garden-plot problems by growing in pots.

Potted plant

You can plant your vegetables in containers at the same time you would plant in the soil.

Photo Courtesy www.RareSeeds.com

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Container-grown vegetables are just as delicious and nutritious as those that are grown in the ground, and nothing tastes better than your very own fresh-picked, homegrown produce. Being able to step out your back door to pick a ripe tomato whenever you need one is not only convenient and delicious, it’s a great way to save money. And, you have the satisfaction of growing it yourself.

Growing vegetables in containers is no more difficult than growing any other potted plants. By paying attention to a few special requirements, you can grow most vegetables in containers on your deck, patio, balcony, and even on the rooftop.

What better way to try your hand at vegetable gardening, than by growing containers of some old-time favorites like beans, lettuce, Swiss chard, tomatoes and herbs? Container vegetable gardens bring a bounty of fresh, good-tasting vegetables to the tables of city dwellers, gardeners that have limited space, and those who are seeking a healthier alternative to buying tasteless, pesticide-laden market vegetables.

There are quite a few advantages to growing vegetables in containers. Not only can you provide the ideal soil mix for each particular vegetable and easily manage any root competition between plants with just a little thinning, you can often plant earlier in the season. As soon as the temperature becomes moderate and the sunlight becomes stronger, the soil in containers warms up more quickly than the soil in the ground. And if frost threatens, you can move the containers to a sheltered area, or cover them with frost cloth until the danger passes. Another benefit of growing container vegetables is that your garden won’t be taking up much space. You just need a sunny spot or two that will provide the warm sunshine for the containers.

You can plant your vegetables in containers at the same time that you would plant in the soil. Depending on what types of vegetable you want to grow, you can start seeds directly in your containers, grow transplants from seeds that you’ve started indoors, or purchase transplants from the nursery.

CONTAINER TYPES

There are many types of materials to choose from; which one to use is a matter of taste.

Always avoid containers made of treated wood, as they may contain toxic chemical compounds that could be absorbed by your vegetables.

There are a few things to consider when choosing the container type for your garden.

Concrete and stone. Concrete and stone containers and planters are very durable, offer insulation from overheating and are porous, but they are very heavy.

Plastic. Plastic containers are lightweight and economical, though they vary in durability, porosity and the ability to insulate the soil.

Terra-cotta. Unglazed terra-cotta pots are popular because they’re moderate in weight, insulate very well, and they’re very porous and economical. However, the soil can dry out quickly due to evaporation unless they’re treated with a waterproof sealant before planting.

Pottery. Glazed clay pottery is light, waterproof and quite durable. Handle them with care, as these types of pots are subject to breakage and are often less economical than other materials.

Wood. Wood is natural, offers good insulation, and is very porous. Seal the inside with a waterproof sealant to protect them from fungal rot.

Galvanized metal. Galvanized troughs and tubs’ metallic finish has an appealing rustic look, yet they are lightweight and will not rust.

Hypertufa. Modeled after ancient stone troughs used to hold water and feed for livestock, these troughs are made from an artificial stone product.

HOLES AND FEET

Be sure to select a container with adequate drainage holes. Many pots have only a single hole at the bottom that’s just a quarter-inch wide or smaller. If that’s the case with the container you want to use, enlarge the hole or drill more of them in the bottom prior to planting, keeping a few inches of space between the holes.

The next step is to keep the drainage holes from plugging up by either lining the bottom of the container with a porous landscape fabric or covering the holes with some plastic mesh. Then add an inch of pea gravel or large-sized bark chips to help keep the loose potting soil from washing down and out of the holes. Water will still be able to pass through the openings. Always put something — bricks, wooden blocks, or “pot feet” — under the containers to keep them off the ground. Just a few inches is all that’s needed to facilitate drainage, prevent the drainage holes from getting plugged, and to help prevent any disease organisms that could be in the soil from reaching the plant roots if the containers will be sitting on the ground. You will avoid rotting your wooden decks and staining of concrete patios by providing good air circulation if you put something under them. If you follow these guidelines and take the time to carefully select and prepare your containers for planting, you’ll be well on your way to getting your “contained” vegetable garden off to a healthy start.

THE BASICS

The four basic things you need for a successful container vegetable garden are an appropriate-sized container, good potting soil, organic all-purpose fertilizer, and plenty of water.

Potting soil: Most potting soil mixes contain organic matter such as peat moss or ground bark, which holds onto moisture and nutrients. They can also contain inorganic products such as perlite to improve drainage and to keep the soil from compacting. These fast-draining potting soils need to be watered often. Maybe even once a day when it’s really hot.

Choose an organic soil that is suitable for container growing. It should be stated on the bag.

Organic fertilizer: Some potting soils have some fertilizer in the mix, but not enough sometimes to last through the growing season, so you may need to mix in a little extra organic fertilizer when you’re ready to sow or transplant. It’s best to fertilize frequently, about every three weeks, but with less than the recommended amount so you don’t over-fertilize and shock the plants. This will promote steady, healthy growth. Fertilizers and nutrients are also essential components of growing healthy container vegetables.

Sunlight: Whatever vegetables you plant, make sure your container will get enough direct sunlight. During the spring season, they typically need at least six hours of sun per day with good air circulation. When midsummer comes around, some vegetables, such as your broccoli, cauliflower, greens, leeks, and onions may require some shading in the late afternoon to prevent them from bolting (producing the flowering heads that then will produce seeds). So be sure to check the plant tag or seed packet for specific light requirements.

If you live in a warmer part of the country, be cautious about putting your containers in an area that could get a little too warm or hot from the reflection of a building or from pavement, or from a cement patio that’s generating too much heat. The eggplants and melons love the heat, yet the cucumbers, peppers and summer squashes would appreciate not being overheated! Put the large, heavy containers on dollies or carts so you can move them around and provide a little reprieve from the heat.

If you live in a cold climate, you can give your vegetables a head start by placing the pots near a south-facing wall and grow broccoli, cabbage, cauliflower, and the many varieties of greens.

Water: You need to be consistent with regular watering practices. Remember that the soil in containers dries out more quickly than ground soil, so your potted plants will need that regular irrigation. Vegetables are especially susceptible to wilting and can be slow to recover. Plants that are water-stressed will not produce up to their full potential. As a general rule, keep the potting soil moisture like a wrung-out sponge. Dig down into the soil a few inches and feel how wet the soil is. You can use a moisture meter that will tell you whether the soil is wet, moist, or dry. If you have quite a few containers and aren’t home much, consider installing a drip irrigation system to help you keep everything sufficiently watered.

COMPACT-SIZED VARIETIES

The varieties of vegetables that are available for us to choose from now are limitless, even for containers. There are many varieties of compact-sized plants of beans, cucumbers, eggplants, peppers, squashes, tomatoes, etc. There are even baby-sized varieties of beets, carrots, bok choy, peppers, and tomatoes that produce yields similar in volume, if not size, to those growing in the ground.

The great thing about growing vegetables in containers is that they provide a beautiful and ever-changing landscape, even when they’re weeks away from harvest. As the season progresses, you can enjoy watching the fruits of your labor grow into ripeness. There’s nothing better than watching the beans twine up a pole, tomatoes that get bigger and bigger each day, and watching the peppers turn orange or red in color. There’s even something about watching the broccoli and kale flower, knowing that you will be collecting your own seeds and saving them for next years’ planting.

Unlike the plants living in the ground, container plants can’t go for long without water and nutrients when they need them, so just keep in mind that these containerized plants are counting on you, and with a little TLC you can keep your contained bounty growing happy and healthy.


Gwen is a private landscape consultant and designer, specializing in residential garden design. Gwen has written a Q&A garden column in her local newspaper, The Press Democrat, for more than 20 years.