Tomatoes are an extremely popular food in Western society. It is frequently used as a component of meals, if it does not feature prominently. Tomato is a fruit to a gardener and a vegetable to a cook, meaning that it is a seeded product of a plant (fruit) but is served with vegetables in a dish. It originally comes from Mexico, which is no surprise given its use in Mexican cooking.
Its Mexican origins probably gives you a hint about the climate it likes, too. It enjoys warm weather and can grow in almost any frost-free condition. If winters are frosty in your region, plant at the beginning of spring.
Varieties of Tomatoes
Tomatoes come in hundreds of different shapes and sizes. Indeterminate varieties grow tall or in vines and have only a couple of branches that bear fruit. They require trellising and as a result can only be grown outdoors. Determinate varieties are more bushy with multiple branches that bear fruit. Indeterminate varieties produce fruit for a longer period than determinate varieties.
There are too many varieties to properly cover in the scope of one general article. It’s important to realize though the sheer number of varieties available including many delicious types that many people will never have seen on supermarket shelves. Talk to your local growers about what varieties they have available.
A ‘beefsteak’ tomato, a large and tasty variety rarely seen in shops
Planting Tomatoes
Tomatoes are easily started from seed. You can get an early start on the season by starting them inside. Sow seed in punnets or seed trays full of seed raising mix. When to start planting depends on the climate. In most warm areas, especially the tropics, you can get away with sowing seed at any time of year. Remember that tomatoes detest frost, so if you live in a chilly area you will want to sow seeds indoors about four weeks before the last frost. Keep the trays or punnets covered with a plastic food wrap to increase the humidity and place in sunlight.
Once seedlings have formed a few leaves they can be pricked out in to pots. They will last a few weeks in pots or until they have grown to a height of 4-6 inches (10-15cm). Once they grow close to this size begin hardening them off in preparation for transplanting.
The soil of their final position should be warm, exposed to plenty of sunlight and the soil should be warm. pH should be around 5.5-7 – nothing too hard to achieve.
Transplantation should occur on the warmest day possible that is also a little cloudy. Look at forecast and if it looks like a warm yet overcast day is coming up soon, plan to transplant then. Tomatoes hate being transplanted in chilly conditions. Soil temperatures above 12°C are ideal. Plant them in the ground with the first leaves on the stem just above the level of the soil.
Spacing tomatoes is a bit of an art. The minimum space between plants is around 2 feet (60cm). When planted this close they will need lots of water. A less risky spacing is around 3 feet apart. Tomatoes do not have to be grown up trellises, but they will take up a lot of ground space with their sprawling vines if not.
Tomatoes can be grown from seed without transplantation. They can be sown when the soil temperature is a nice and warm 12°C or more. Sow in drills and thin to the final spacing of 2-3 feet apart. Tomatoes need a long growing season so most people start indoors and transplant, but if your climate will provide about 8 hours of sunlight and temperatures between approximately 15 and 30 degrees for 3 months straight then growing in the ground should be just fine.
Growing Tomatoes
Tomatoes take around 60-90 days to reach maturity, depending on the variety. The temperature range tomatoes prefer is around 12°C to 35°C. If the temperature gets any higher than this the tomatoes will need to be shaded. This can be done using a man made canopy or tarpaulin. If the tomatoes have not been staked their foliage provides a natural canopy, so savvy gardeners who live in very hot areas can plan to not stake their tomatoes.
If you do need to trellis, a stake is the easiest solution. Tie the branches loosely to the stake with a soft gardening tie in a figure of 8 pattern. As the plant grows, trim the side shoots from the stem by pinching them with your fingers or snipping them with a pair of scissors. This will ensure the plant puts all its effort in to growing the larger, fruit-bearing parts of the plant.
A commercial tomato growing operation. Note the cage-like trellising system
Weed regularly and water even more regularly. Tomatoes love soil that is constantly moist but not soaked. Over-watering soil will make the plants more prone to diseases and also quite literally ‘water down’ the flavor of the fruit. Try and keep to a regular watering schedule and use a mulch to keep soil moist in between waters.
If soil has been pre-prepared with a fertilizer it won’t need much more until the fruit has started to show. An organic fertilizer every month from then on will do the trick. Many people like to use a high potash fertilizer, as well.
For more information on advanced pruning of tomatoes, see this article.
Growing Tomatoes in Containers
Determinate (bush) types of tomatoes work well when grown in pots. Especially good are cherry tomatoes. With a large enough pot and a stake you could probably get away with growing some vining varieties in pots as well. Remember that plants grown in pots need more water than those in the ground.
Harvesting Tomatoes
Tomatoes are harvested by simply snipping the stem just above the fruit. They should be fully mature before they are picked. Top them a month before the frosts are due to ensure they reach maturity. If maturity is unable to be obtained before the frosts set in (or if birds or other animals are stealing your tomatoes), the entire plant can be uprooted and hung upside down in a shed to ripen. Fruit that is slightly colored at the time of uprooting do best with this technique.
Tomatoes can be cooked and put in jars to store. They can also be frozen as long as they are skinned and cored first before simmering in a pot for about 5 minutes. They last about a week fresh.
Very large tomatoes, such as the beefsteak varieties, may need to be dried out for a period after harvesting. Dry in a dry (not humid) place, either inside or outside.
Threats to Tomatoes
Numerous issues plague tomatoes. Rot can set in if watering is irregular or if soil is too acidic. Small bugs can get to your plant – use an insecticide to control them. Tomato plants often wilt from the base upwards. Remove the affected leaves as they grow. Sometimes tomatoes need a boost of magnesium if their leaves are yellow.