For those without garden space, be assured that growing tomatoes in pots can be as productive a method of growing tomatoes as using a traditional garden plot.
Perhaps the most common mistake is using too small of a pot. I've made this mistake myself.
I once tried growing tomatoes upside down in a gallon sized sphagnum moss-lined wire hanging basket. Well, I did harvest a small crop but the container had to be watered twice or more per day during the hot months and even then the leaves soon wilted. I won't repeat that mistake. If you're growing tomatoes in pots then you should use larger pots that don't lose moisture quickly. How large? Here are some recommendations:
Tall growing tomato varieties (indeterminates) should be planted in pots holding at least two gallons of soil mix. Reasons to use large pots:
Small tomato varieties (determinate, bush type) should be planted in pots holding at least one gallon of soil mix.
Your pot should have a drainage hole in the bottom to keep your plant from sitting in water. Add some material like gravel or a mesh screen to the bottom of the pot before adding soil so it doesn't wash out.
Most commercial potting soils from your garden center will work fine for growing tomatoes in pots. Rarely will soil from your backyard contain enough organic matter or be friable (crumbly) enough to use. You can even buy commercial tomato soil that is optimized for growing tomatoes. Or you can make your soil mix. Mel's mix is a good choice.
As I mentioned in my tomato soil article, if you want to make your own perfect soil mixture, follow Mel Bartholomew's simple recipe from All New Square Foot Gardening. As author of the best-selling gardening book of all time, Mel knows a thing or two.
A handy table detailing the amount of potting soil needed and volume of many pot sizes is found at BonniePlants.com.
You can grow any size tomato variety if your pot is large and you can stake the vines.
For small spaces there are many miniature-sized tomato plant varieties, some of which are only a foot tall. These will all bear an abundant crop of tasty fruit. A few varieties that are especially suited for small spaces:
You should review the information in the planting tomatoes article to familiarize yourself with hardening off seedlings, planting depth, and other details. The difference may lie in the need to fertilize. Many bagged soil mixes come pre-fertilized so you should follow the bag instructions.
To keep your vines in line you should stake all but the miniature-sized varieties. The easiest staking method is the single-stake method. Pruning tomato plants makes it much easier to single-stake.
Keep the soil moist but don't drown your tomato plants. You don't want to wait until the leaves wilt before watering, as studies have shown that tomato plants are more vigorous when they are not allowed to wilt. However, don't worry. They'll typically bounce right back if you're a bit late on your watering chores.
Water the base of the plant, not the leaves. Having wet leaves all night encourages tomato plant diseases.
By following some of these container tomato growing tips, I think you'll be pleased with the quantity and taste of the tomatoes you'll be harvesting this summer.