Just because you don't have a big backyard doesn't mean you can't reap the benefits of a vegetable garden. A sunny window ledge, balcony, patio, or roof
deck with six or more hours of full sun will provide plenty of space to cultivate and harvest veggies. Recently, I helped some friends create a vegetable
garden on their South End roof deck. We potted eight containers using about two cubic feet of garden soil mixed with compost. Salvaging containers used
in years past and buying about $125 worth of plants, soil, and new containers, we planted a whole garden, one they can begin to enjoy in just a few weeks, when the herbs need pruning. Want to try it yourself? Here's a primer to get started. - ELLEN WELLS
1. Proper drainage is key
Potted vegetables don't like to have "wet feet," or roots. Make sure your containers have at least one drainage hole to allow excess water to drain away. To aid drainage for containers bigger than about 16 inches in diameter, fill the bottom third of the pot with materials that will create empty spaces, such as broken shards of terra cotta pots, large stones, or styrofoam peanuts. The peanuts have the benefit of being lightweight, allowing you to move larger containers from one place to another. Cover the material with a layer of newspaper to prevent soil from sifting out of the drainage holes. It'll also make it easier to reuse the material in next year's garden. Filling smaller containers entirely with a soil mixture is fine.
2. All dirt isn't equal
Choosing appropriate soil trips up beginning gardeners. Filling a container with backyard dirt is never an option. Plants need to sink into something that lets their roots grow easily and soak up the water, air, and nutrients around them. Think of the appropriate soil as being a spongy bread with evenly spaced air pockets. Use a soil specifically designed for containers. Or, add a good-quality soil used for the garden in a 3:2 ratio with compost. We used a Scotts brand garden soil mixed with a compost from a local community garden. Another trusted soil for container gardening is Coast of Maine's Cobscook Blend Gardening Soil premixed with compost and peat moss for aeration. Some mixes contain fertilizers. We added an organic fertilizer. We also lightly moistened and mixed the soil before adding to the container. Fill to within two inches of the rim.
3. Pick the right plant
When shopping for vegetable plants, look for healthy green leaves that are turgid and without marks or spots. Lackluster plants have experienced some stress, making for a slow start in their development. Many smaller pots of veggies you'll see in the garden center will have several small plants clumped together. When you plant these as one large group in a pot, they'll compete for food, light, and air, and only the strongest will survive. You can increase their chances of survival if you gently tease the roots apart with your thumbs and plant them in groups of two or three. Larger potted vegetables such as tomatoes and eggplant will have just one or two plants per pot. Just remove the plant and its rootball from the original container, and loosen the roots slightly by pulling the rootball apart about a quarter-inch with your fingers.
4. Keep seedlings snug
Make a hole slightly larger than the rootball and insert the plant so its rootball is below the soil line. Tamp soil around the plant, making sure the rootball is completely covered with soil. This prevents the rootball from drying more quickly than the surrounding soil. Water gently until it runs from the bottom of the pot. The plant tag may say to plant six inches apart, but don't hesitate to plant herbs, lettuces, and other small veggies closely together when planting in containers. Those recommendations are for traditional garden bed locations, where gardeners usually want to maximize their plants' growth. When container gardening, planting closely lets you squeeze more plants into a small area, while also keeping their growth in check.
5. Support vines and bushes
Bushy and vining plants such as tomatoes, peas, and beans will need some support as they grow and their veggies develop. Use a cage for potted tomatoes, eggplant, and other bushy veggies, and as the plant grows, guide the branches through the supports. This also keeps the developing fruits off the ground where they can develop rot. A trellis can provide support for vining veggies like peas, beans, and squash. There are many different designs of cages and trellises, and you may find your veggie may need some added assistance from string or a twist-tie to hold it secure. If space is limited, consider co-planting large containers. Plant basil alongside a potted tomato, or oregano along with eggplants. Lettuces will succumb to hot weather in late July, but you can get an extra week or two's harvest if you plant them in the shade of a vining bean.
6. Mix it up
A mixed herb container makes a lovely centerpiece. Keep near your grill for easy access. Once herbs like basil and mint begin to flower, their growth slows. Pinching off flowers helps keep the herb growing, and also encourages lateral stems to grow, forming a bushier plant. Water your vegetables, preferably in the morning, until water flows from the bottom. During hot weather, plants may need watering two or more times a day. A sure sign they need watering is when their leaves become limp. If you have lots of containers, consider using an automatic watering system. One of the most common is a hose with smaller tubes emerging from it that can be placed into individual pots. Attached to a spigot, it can be programmed to come on at predetermined times, keeping your plants watered even if you're away.