With their vibrant colors and freshness, tomatoes are a popular vegetable known for their prolific yield and versatility in cooking. A member of the nightshade family, tomatoes come in approximately 10,000 varieties, with colors ranging from pink to purple, yellow to white, and even black. Tomatoes are often categorized into indeterminate or determinate varieties, and it is important to know the difference when deciding which to plant.
- Determinate: Also known as bush tomatoes, determinate varieties grow buds that flower and tend to fruit over a two-week period before stopping. They are more compact in size, as they stop growing when they reach 3 – 4 ft. tall, which makes them ideal for gardeners with limited space.
- Indeterminate: If you have a large amount of space, you can consider growing indeterminate varieties. Since they grow on vines, they will need supports such as trellises or tomato cages. This type will grow continuously until killed by frost, sometimes growing up to 10 ft. These plants produce lateral shoots branching from the main stems and have a much longer growing period than determinate tomatoes.
- Heirloom & Hybrid: Hybrid tomatoes are tomatoes typically found in supermarkets and groceries. Consisting of a cross between several cultivar types, hybrids are mass produced and easily harvested, incorporating several favorable characteristics including disease resistance, flavor, and storage length. Heirlooms are specialty tomatoes that have been grown without crossbreeding for 40 years or more. While they have better flavor, they cannot be shipped long distances due to their fragility, and are usually found in farmer’s markets. If you are an experienced gardener, you can choose to experiment with heirloom varieties, which take more effort to grow.
- Tomato varieties: Some varieties include cherry and grape tomatoes, Roma tomatoes, and beefsteaks. Small and easy to grow, cherry tomatoes are recommended for beginners. Due to their sweetness, Roma tomatoes are ideal for tomato paste or sauce. Beefsteaks are large and firm, holding up well when sliced, which makes them ideal for sandwiches and burgers.
Conditions for Growing Tomatoes
Tomatoes are warm weather plants that are grown during late spring or early summer, except in zone 10, where they are grown during the fall or winter. Although most varieties need 100 days to mature, some varieties only take 50 – 60 days.
When: Tomatoes will not grow in temperatures below 50°F, so you should plant them when the temperature is consistently above 55°F. You can also start seedlings indoors 6 – 8 weeks before the last spring frost date. The ideal soil temperature for growing tomatoes is 60°F. They do not like temperatures over 90°F, so it is best to cover them or place them in shade during times of sustained heat.
Where: Tomatoes can be grown in raised garden beds or containers. Raised garden beds are recommended because they allow you to control the soil quality and maintain a consistent temperature during changing seasons and temperature fluctuations. The soil also warms up faster, which is particularly beneficial for tomatoes. They can also be planted indoors in trays.
The ideal soil is sandy loam that is loose, well-draining, and rich in organic matter, with a soil pH of 6.5 – 7. However, they can tolerate other types of soil except for heavy clay. If your soil has drainage problems or has subpar composition, you can consider growing your tomatoes in metal raised garden beds that are at least 12 inches tall. Select a location that receives direct sunlight for at least six hours.
Spacing is important to consider for tomatoes. Bush tomatoes should be planted two feet apart while indeterminate varieties can be grown closer, around 18 – 24 inches apart. Good companion plants for tomatoes include marigolds, basil, and garlic. They should not be planted next to members of the cabbage family as they can stunt the growth of tomato plants.
How to Plant Tomatoes
You can plant seeds indoors ½ inches deep in containers such as seed starting trays. Cover with ¼ inch potting soil and moisten the top layer. Some gardeners choose to supplement with LED grow lights and heating mats for better results. Fertilizing is optional at this stage. Wait until the seedlings have 2 – 3 leaves before applying a weak, water-soluble fertilizer at ¼ strength. Crystalized salts at the bottom are an indication that you have overfertilized.
You can transplant your seedlings when the danger of frost has passed and the soil reaches 60°F. Before transplanting, make sure they are hardened off and gradually introduced outdoors. Remove the plants from their containers and place the root ball deep enough so that the bottom leaves are just above the surface of the soil. Tap the soil firmly and then water the plants. Compost should be added to the soil, along with fertilizer such as organic tomato fertilizer or bonemeal to the planting bed to encourage growth.
Care: Mulch with a three-inch layer of straw five weeks after transplanting to retain moisture and suppress weeds. Avoid high nitrogen fertilizers if your soil already has adequate nitrogen levels, which can result in leaf growth and delay flowering and fruiting. A few weeks after planting, you can use a fertilizer with a higher nitrogen content, such as liquid seaweed, fish emulsion, or an organic fertilizer every two weeks, starting when the tomatoes are 1 in in diameter. Later extend the frequency to three or four weeks.
Tomatoes benefit from deep, consistent watering the first few days they are in the ground. Later, add 1 – 1.5 inches of water per week during the growing season, which should be adjusted depending on weather conditions. You should water your plants early in the day to ensure sufficient moisture.
If you are growing vining tomatoes, you can prune your plants by pinching off suckers, which are tiny stems and leaves that appear between the main stem and a branch. This will improve air circulation and result in larger fruit. If you are not getting flowers, then the plants may be experiencing a lack of sunlight or water. If your plants are producing flowers, but no fruit, then it may be because of the above factors, or too cold or hot temperatures. Low humidity and lack of pollinators could also be a factor.
Pests: Tomatoes are susceptible to several insect pests, including aphids, cutworms, flea beetles, and whiteflies. To get rid of them, spray the plant with water or remove insects by hand. You can also apply insecticidal soap to the insect or horticultural oils. You should refrain from using insecticides, which can kill beneficial insects as well, unless you are experiencing a severe infestation and the other methods have not worked.
Since fungal diseases are common, you can consider using disease resistant cultivars and rotate crops every 2 – 3 years. Blossom-end rot, which is caused by a calcium deficiency, results in dark, sunken spots in the fruit. Once the disease develops, you need to throw away the fruit and focus on preventing its spread. Since inconsistent watering is a main cause of calcium deficiency, adjust your watering schedule and use mulches to conserve moisture.
Another problem is early blight, which starts as small dark spots in the foliage, with larger spots having concentric rings. To reduce fungal problems, prune or stake plants to improve air ventilation, and strip off the lower leaves. Apply copper based fungicides early before the symptoms normally start to appear.
How to Harvest and Store Tomatoes
Tomatoes can be harvested at the end of the growing season, usually during late summer. While some gardeners prefer vine-ripened tomatoes, others choose to harvest them when they are half ripe, and are a light orange or pink color. A reason for picking tomatoes earlier is that they are less likely to split or break, especially for indeterminate varieties. This depends on individual preference, and you can try both methods to see which works best. However, when temperatures drop below 45°F, you should harvest all remaining tomatoes, regardless of color.
Gently squeeze the fruit to make sure it is firm. To harvest, cut them off using garden clippers or pick them by hand. Store them in a cool shady location with good air circulation and temperatures between 65 – 70° F and wait for them to ripen. Do not place your tomatoes by the windowsill, which can cause the skin to harden and rot. Also do not place them in the refrigerator, which halts the ripening process.
Once ripe, you can store them in the refrigerator, keeping in mind that it is best to eat them in a couple of days. There are many ways you can enjoy your tomatoes – in sauces and salads, roasted, canned, and more. You can also preserve cherry tomatoes to extend their edibility.