Tomatoes originally came from South America, where they had adapted to the humid and warm climate of the region. In fact, for a tomato to sprout from a seed to a fruit-bearing plant, over 100 days of full sun and heat are required. Unfortunately, this is bad news for aspiring tomato gardeners in most U.S. states.
The good news is that if you live in an environment that is too cool for growing tomatoes from seeds, there are other options: you can simply buy or grow (indoors) your own tomato seedlings, and shield them from the cold until the summer comes, when you can transplant them. Of course, there are downsides to this. For one, tomatoes don’t always take well to being transplanted, and in fact such a sudden change may slow their growth, injure the plant, or even lead to its demise altogether.
People who don’t have a lot of space for their gardening hobby might try to cultivate their tomatoes in pots, and it may very well work for them, but sadly when it is time to transfer the plant outside, tomatoes that began their lives in pots are particularly prone to transplantation shock as compared to those who started their lives outdoors in more natural surroundings. Because of this, if you plan to cultivate your tomatoes in pots, there are a few measures that you need to take to ensure that they will grow well:
1. Examine the plants closely before you buy. As the old saying goes, you reap what you sow. A healthy plant from the beginning is much more likely to lead to a healthy tomato fruit. Go with a nursery that has a good reputation, and that is willing to offer refunds or replacements if your plant dies too easily. Go for the greenest-looking plants with stems and leaves that don’t appear soggy or wilted. If the leaves are discolored or splotchy, avoid these as well, since they are possible signs of disease. If you happen to reside in a very humid area, it is especially important that you choose a hardy, healthy-looking plant, since areas like these are a breeding ground for botanical diseases.
2. If you have the choice, go with smaller tomato plants instead of large ones. Lately, more and more supermarkets and big box garden centers have been offering large-sized tomato plants that have already begun to bear some fruit. If you don’t care to transplant these into the ground and just want to leave them in their store-bought container, this isn’t a problem, but if you plan on moving the plant into a bigger container or even just into the ground directly, go with plants that have not grown more than about a foot in height. Small plants tend to suffer less from transplantation, and will recover and grow faster than larger ones when they are transplanted into your garden. If you are planning to transplant the seedlings that you grew yourself, however, it’s best to transplant them when they are even smaller—no less than 4 inches, and no more than 8 inches in height.
3. Don’t be rushed; wait it out until the spring or even summer. Because pots don’t insulate as well as earth will, it’s best to go through the transplantation process when the temperatures outside are at least 70 F during the day. If there’s an unforeseen drop in temperature, just bring them inside and cover them up until the cold is gone.
4. Pick a pot of the right size. Since tomato plants tend to spread their roots out in a wide pattern, you need a pot with a diameter that can accommodate. How big your pot is will depend on how large your specific variety of tomato is. If it’s a small bush, you may only need a 5-gallon bucket. If it’s a particularly large heirloom tomato variety, for instance, you might need a container that can hold as much as 15 gallons.
5. Consider the soil quality. You may have a habit of using normal commercial gardening soil for your plants, but avoid this with your potted tomatoes! Pots tend to squeeze and contain the dirt, which can deprive the roots from proper air circulation, in addition to possibly promoting certain kinds of disease. Your best bet is to buy potting soil made specifically for container gardening.
6. Acclimate them before you transplant them. This may seem pointless, but it honestly makes a difference. Put your potted plants in a shady place near your garden for a few days so that the plants can get used to the outdoor environment, to the temperature, wind, and humidity that might be different from its indoor conditions. Give them as much water as you usually do, but otherwise leave them alone. If you’re buying from a nursery or the garden section of your local big box store, this might not be a necessary step, though, because they may already have been stored outside.
7. Make sure the roots are deep. When you transplant into another container, be sure that the plant has been placed deeply enough; you may even want to bury the first few leaves at the bottom of the stalk. In addition, it might be helpful to get rid of any flowers, so that the plant might instead expend its precious energy solely on strengthening its roots.
8. Take special care of your plant. For the first few weeks, keep a close eye on your transplanted tomato bush. You may want to add fertilizer and give it some extra water to prevent the soil from getting too dry. Since the plants are particularly fragile until their roots have gotten over the shock and once again begun to expand, try to place them in a spot where they are protected from the elements as much as possible.