No place to dig a garden? You can still grow your own food! You can raise substantial amounts of many edibles in containers on a patio, deck, porch or balcony. Container gardening has grown rapidly recently and we have developed an increasing number of compact and dwarf varieties intended to succeed in small spaces. Containers also make it easier for you to control the soil, light, water and fertilizer.
Here are some tips for getting started with container vegetable gardening:
Bigger is better. The greatest challenge of container vegetable growing is watering, since soil dries out faster in pots than in the ground. A larger volume of soil won't dry out as fast, so choose the biggest pot you can. It's fine to mix compatible plants in a single large pot. Make certain that any container has holes so excess water can drain away from the soil.
Plan for watering. So-called "self-watering" containers have a reservoir beneath the soil topped with a grid through which the roots can reach down to the water. With these containers you won't have to water as often, but you still have to keep that reservoir filled. In the hot summer mature plants will empty that reservoir fast, so you may have to fill it daily. Spread mulch over the soil in pots just as you would in a garden, to keep moisture from evaporating. Planning a summer vacation? It may be wise to stick to spring and fall crops, such as greens, peas and radishes, and let the pot garden go fallow while you're gone.
Start with herbs. They are easy, especially if you begin with transplants, and will add a fresh-grown taste to almost any meal. Just remember to give them the conditions they prefer. All herbs need full sun, but some, such as rosemary, prefer dryer soil and fewer nutrients; basil needs more fertilizer and watering.
Move it. With pots, you may be able to finesse a sun shortage. Place a wheeled pot trolley (available in garden centers) under a large pot and move it to follow the sun. For example, move it into the sun in the morning; in the evening, when you want to sit on the patio, scoot it out of the way.
Green up. Baby greens, such as lettuce and spinach, are perhaps the simplest vegetables to grow, beginning in spring when they will tolerate cool temperatures. Sow seeds right in the pot. They will take a week or more to sprout, but then will quickly reach a harvest size of three to four inches. Use scissors to snip off only the largest leaves and you can keep your harvest going for several weeks. Then pull out the plants and re-sow.
Accept the challenge. Everybody loves tomatoes, but they take some work. For pots, seek out varieties specifically recommended for containers, that are "determinate"--meaning they will grow to a certain size, then stop and bear all their fruit in a few weeks. You will need a large container, at least 20-24 inches in diameter. Tomatoes sprawl and the fruits get heavy, so provide a cage for all but the most dwarf determinate tomato varieties. Or install sturdy stakes in the container when you plant and be attentive to tying new shoots to the stakes.