The larger the container, the better. The plants will produce more fruits and be easier to take care of. Ideally, choose a container with a capacity of 25 to 30 gallons; a durable plastic pot or a whiskey half barrel works well. You can even use a plastic garbage can. If your summers are very hot, use a light-colored container that won't absorb the sun's heat and burn the plants' roots. Don't use a container made of metal; it will get too hot for good root growth and may contain zinc, which is toxic to plants at high concentrations.
You can grow almost any variety in containers, but disease-resistant types will require less maintenance. For heavy-producing, large-vined indeterminate varieties, try 'Big Beef', 'Better Boy', and 'Tomande'.
For some smaller-vined determinate varieties that produce less fruit but a little earlier, try 'Celebrity'and 'Sunmaster'.
If you want to grow cherry tomatoes, 'Sugary' is a good choice.
If you love tomatoes (and most gardeners do!) but don't have room to grow them in your yard, don't despair. You can grow tomatoes in a container on your deck or patio and still get good yields. Plus, you don't have to limit yourself to just growing dwarf, small-fruited varieties. Almost any variety can be grown in a container if you choose the proper sized pot and follow the simple steps below.
Preparing the Pot
One major advantage of growing in containers is you can keep plants free of common soilborne fungal diseases, such as verticillium and fusarium wilt. A soilless potting mix provides a nearly sterile environment for the plants. Don't add unsterilized compost to the soil or line the bottom of the container with rocks; both may introduce disease to the potting soil. Add one ounce of pelletized dolomitic limestone per gallon of potting mix to protect against blossom end rot, which results from a deficiency of calcium and magnesium.
For proper drainage -- and to avoid the root rot that can result from perpetually wet roots -- drill six 1/2- to 3/4-inch-diameter holes into the bottom of the container if they don't have them already. Cover the holes with window screen to prevent soil from washing out. To keep the container out of contact with the ground, which can allow transmission of soilborne diseases, set it on four bricks.
Where to Plant?
Tomatoes need at least 6 hours of sunlight each day but will produce best with 8 hours. Set your container in a sunny spot, preferably with a hose nearby for easy watering. If you live in the south where summers are hot, position pots where they get afternoon shade. Where daytime temperatures exceed 90° F and night temperatures reach 70° F, the pollen on the tomato blossoms can become sterile, ceasing or deforming fruit production. Afternoon shade helps minimize this condition and will also keep the soil from drying out too quickly. Also, grow heat-tolerant varieties that can produce fruit even in hot weather, such as 'Sunmaster'.
Planting & Feeding
Once the container is in place, fill it to within 2 inches of the top with soilless potting mix. Mix a controlled-release fertilizer into the top 3 inches of soil to feed the plants through late summer. If you live in an area with an extended growing season, you may have to supplement feedings with a water-soluble fertilizer (at the recommended rate) when growth slows in late summer. For an organic option, feed plants twice a week with fish emulsion.
Plant two tomato transplants per container. After planting, water transplants well, then set up a cage to give them support and keep them off the ground as they grow. Measure the circumference of the rim of your container. Cut an 8-foot-wide piece of steel reinforcing wire to the size of the circumference plus 6 inches for overlap. Use wire with 6-inch holes so you can easily stick your hands into the cage to water and prune the plants and harvest the fruits. Wrap the cage around the container with the lower edge on the ground, then secure the cut ends with wire. For support, drive two steel fence posts into the ground next to the cage and attach them to the cage with wire. If needed, use tomato ties to secure the vines to the cage.
In cold areas, wrap two layers of clear plastic around the cage in early summer and fold it over the top, leaving an air hole for ventilation. Remove the plastic when daytime temperatures reach 70° F. Water plants when the top 3 to 4 inches of soil are dry. Avoid wetting the foliage, and soak the soil until you see water draining through the bottom of the container. After the plants begin to set fruit, water them daily, especially on hot, windy days. When branches extend beyond the cylinder, tuck them back inside. If you live where summers are hot, don't prune the plants; they need to develop foliage to shade the fruit from strong sun. In cooler regions, pruning will help fruit produce sooner. Pinch back suckers as they grow, and prune the tips of growing stems late in the season, removing buds that won't have time to bloom.
Also, remove fruit before the first frost and either eat them as green tomatoes or ripen them indoors by wrapping the fruits in newspaper and keeping them in a 70° F room. Move the containers to a protected spot or wrap them in blankets in fall when cold weather threatens.
Question of the Week
Q. Is there a repellant or some other harmless way to keep rabbits from eating marigolds and veggies in my garden? I have tried raising the beds and covering the plants, but they still get in.
A. Rabbits love vegetables and flowers, especially in spring when there's little else to eat. The best way to keep these critters out of a garden is to erect a wire fence (with small holes), or make cylinder cages out of hardware cloth to put around individual plants. These barriers need to be sunk 3 to 4 inches into the soil or the bunnies will just dig under them. There are some rabbit repellents available as well, but these will need to be reapplied after a rain, so the most effective way to keep them out of the garden is with fencing.