If you have a limited amount of space, or if you have terrible soil, then you can grow your tomatoes in a container. A number of determinate tomato varieties are specially bred for this purpose, bearing a nice bunch of tomatoes in a small pot.
Any tomato variety with the word “Patio” in its name is probably a sure bet. Good varieties include Black Seaman, Patio Princess, Czech’s Bush, Sophie’s Choice, Silver Fir Tree (also a pretty little tomato plant), Bushsteak (big tomatoes on a little plant), Whippersnapper (its size and yield depend on the size of the container you put it in), Sweetheart on the Patio (cherry tomatoes), Marglobe, Baxter’s Bush Cherry, Gardener’s Delight (also an heirloom, so you can save the seeds from year to year), Balcony, Bush Early Girl, Stupice, Tumbling Tom Yellow.
Large 20 inch plastic pots with saucers are a good bet for these tomatoes. They’re easy to move, store, and sanitize at the end of the season.
Now, the drawback of having a gigantic pot is that it’s going to be super-heavy and difficult to move around. But! There are ways you can lighten the load. I used to have large pots of hibiscus trees in my greenhouse, and they were a pain to deal with. Then somebody suggested that I put at the bottom of the pot, to help with drainage and to keep the pot light, Styrofoam packing peanuts. These didn’t make my filled pots light as air, but I definitely noticed a difference when I was moving these lighter pots around.
So to set up your container, you can start by putting in a cut-out circle from a window screen at the bottom of the pot. This holds in the soil and materials so you don’t get soil and Styrofoam bits coming out when you water. Then you add the Styrofoam peanuts at the bottom, a couple of inches thick. (Be sure you don’t get the biodegradable packing peanuts. These will slowly melt away as you keep watering the plant – and you probably don’t want to see your tomato plant slowly sinking into the pot as they do!)
Then have a bag of good-quality potting soil handy. Don’t use soil out of the garden, as it’s very heavy, both in terms of weight and in terms of porosity. A good “soilless” mix is best for your plant. Most potting soils are made from a mix of peat moss, perlite, vermiculite, and other light ingredients that are heavy enough for plant roots to stay moist and for root hairs to grab onto as the root grows into the soil, yet light enough to keep valuable oxygen near the roots without drying them out. (Roots absorb oxygen from the soil to keep the cells in the root alive – and growing! If the soil is too wet, then the roots can’t absorb oxygen, and the cells stop “breathing” and die – and so do the roots, which in turn affects the plant badly.)
You can improve the soil in your garden, and you can also improve the soil in your pot. Add a cup of dolomitic limestone to the soil in your pot for calcium. You can also add several cups of greensand to the mix. Greensand doesn’t get a lot of press, but it’s great stuff. It’s made from undersea deposits made in the ocean like a million years ago, and is mined in New Jersey, and is high in potassium. Also add a cup of bone meal (calcium and phosphorus) and a cup of blood meal for nitrogen, as well as two cups of kelp meal. Mix it all together. Add your own favorite fertilizer to the mix.
Don’t add all the soil to the pot yet, though. Put some soil at the bottom, then set your tomato plant in there, and fill up the pot until only the top five inches is sticking out. Then, as the plant grows, keep adding more soil. This allows you to plant early. You can cover the pots if there’s a chance of frost very easily that way. Keep the pots in the warmest place in your yard, and if you’re really wanting to plant early, you can lay a sheet of Plexiglas or any transparent plastic over the top and make a miniature greenhouse out of it.
By the way, plant only one plant per pot. This allows it to grow stronger and bear more fruit. If it’s competing with another tomato, it’s not going to do as well.
As the tomato grows, keep adding soil to fill in around the plant. This helps the tomato develop roots all along its stem, making it sturdy and strong, and also all those roots are absorbing all those nutrients you added to the soil.
Fill the pot up with soil to two inches from the top. Then put in a small cage made of concrete reinforcing wire. If your area is particularly buggy or insect-prone, cover the cage with nylon anti-bug netting, and clip it into place with clothespins. Remove the netting only if you’re harvesting tomatoes, adding fertilizers, or pruning. You can even spray for aphids and whiteflies through the netting. Or, if your pests are larger (birds, chipmunks, squirrels, neighbors) wrap the cage up in bird netting, and maybe one of those motion-sensitive sprinklers nearby that will fire streams of water at the offender.
Also add a layer of mulch to the pot to keep the moisture in, to keep roots cool in the summer sun, and to keep little weeds from popping up in the potting soil.
Feed your tomatoes with liquid fertilizer such as fish emulsion, Miracle Gro, compost tea, or whichever fertilizer you prefer, about once a month to keep the plants healthy and the tomatoes.
At the end of the season, when the frost hits and the tomatoes are finished, dump the potting soil into the garden, throw away the Styrofoam peanuts, and clean the pots out and scrub them with a bleach solution to get rid of any insect eggs or diseases that might be harbored there. Then put them in the garage and wait for next spring to start afresh.