Tomato plants (Solanum lycopersicum) are beloved by gardeners everywhere. These leafy annuals grow juicy, flavorful fruits in shades of red, yellow, orange, purple, pink, brown, and green. Plant tomatoes in late spring or early summer once all danger of frost has passed. Depending on the variety, tomatoes can be ready to harvest anywhere from 42 to 110 days from germination.
Determinate or bush tomatoes are more compact, with fruit ripening around the same time before the plant dies back. Indeterminate or vining varieties continue growing and fruiting until the last frost.
- Start tomato seeds indoors six to eight weeks before your region's last frost date.
- Choose a planting site with loamy, well-drained soil and at least eight hours of full sun per day.
- Wait until night temperatures remain above 50 degrees to plant tomato starts outdoors.
- Support tomato plants with stakes or cages once they're ten to 12 inches tall.
- Pinch off or prune suckers on indeterminate tomato varieties throughout the growing season.
- Harvest ripe tomatoes when they're fully colored and firm yet supple, with smooth, shiny skin.
|Botanical Name:||Solanum lycopersicum|
|Plant Type:||Annual, Fruit|
|Size:||3-6 ft. tall and wide|
|Soil Type:||Loamy, Well-drained|
|Soil pH:||Neutral to acidic|
|Hardiness Zones:||3-11 (USDA)|
|Native Area:||South America|
How to Plant Tomatoes
When to Plant
Plant tomato seedlings or starts outdoors after all danger of frost has passed and night temperatures are consistently above 50 degrees.
Selecting a Planting Site
Choose a planting site with well-drained soil and full sun. Wait at least three years before planting tomatoes in a bed where you've grown nightshades (tomatoes, eggplants, potatoes, peppers, and tomatillos) to help keep plants disease-free. Water tomato plants well before transplanting.
Spacing, Depth, and Support
Generally, tomatoes should be planted 18 to 24 inches apart, with three to four feet between rows. Indeterminate types will need more space than determinate varieties. Check seed packets and seedling tags for spacing guidance for the specific varieties you plant. When planting, bury tomato seedlings so that the soil line hits just below the lowest set of leaves. The buried stem will grow roots and better support the plant.
Tomato Plant Care
Tomatoes require lots of bright sunlight to grow and eventually fruit. Plant them in a spot that gets at least eight hours of full sun each day. In warmer regions like the southern United States, tomatoes may benefit from some afternoon shade during the hottest times of the year.
Plant tomatoes in a site with rich, well-drained soil. Choose a spot with slightly acidic loam or sandy loam soil. Work organic compost into the soil a few weeks before you plan to plant.
Water tomato plants regularly to ensure they're getting at least one inch of water per week. Consistent watering will help produce the best-quality fruit.
Water the soil directly rather than sprinkling water from overhead. Keeping the foliage dry will reduce the chance of plant disease. Mulching around tomato plants with organic material like hay, straw, or grass clippings that have not been treated with pesticides can help retain soil moisture.
Temperature and Humidity
Tomatoes can grow well at a variety of humidity levels, but they need warm temperatures to survive and thrive. Temperatures below 50 degrees can stunt growth and damage the plant's ability to produce flowers and fruit. Daytime temperatures above 85 degrees can cause blossom drop, but you can help keep plants withstand the heat by mulching the soil around plants and keeping them well watered.
If your soil is rich or you added enough organic compost before planting, you may not need to apply additional fertilizer throughout the season. You can also apply fertilizer to the soil a few times during the season after planting. Choose a fertilizer that's high in phosphorous and low in nitrogen.
Tomatoes are self-fertile, meaning you don't need more than one plant for pollination. Movement from the wind is usually adequate to ensure pollination. In high tunnels or greenhouses, growers use strategies like tapping tomato cages or stakes to help move pollen from the male to the female parts of the flower.
However, a few different issues can cause pollination issues. High daytime temperatures (over 90 degrees) and low night temperatures (under 50 degrees) can inhibit pollination and cause blooms to drop before they can set fruit. Underwatering can also cause pollination issues, as can using fertilizer too high in nitrogen, which causes plants to put energy toward foliage instead of flowering and fruit.
Determinate vs. Indeterminate Tomato Plants
Tomato plants generally fall into two main categories: determinate and indeterminate. Determinate tomatoes mature relatively early, growing to a mature size of three to four feet tall. All the fruit on the plant ripens within the same roughly two-week period, and then plants die back. Because determinate tomato plants are more compact, they're great for container growing and don't require heavy staking as indeterminate tomatoes do.
Indeterminate tomatoes include most cherry tomato varieties, heirloom tomatoes, and beefsteak tomatoes. Instead of growth stopping once fruit sets, indeterminate tomatoes will keep growing and fruiting for the rest of the season. Because they keep growing, they require sturdy staking and regular pruning. They're also better suited to in-ground planting.
Types of Tomato Plants
There are hundreds of tomato varieties, from heirlooms to hybrids.
- Better Boy (Solanum lycopersicum ‘Better Boy’): This popular indeterminate slicing tomato offers disease resistance, relatively early harvest, and sizeable one-pound fruits.
- Yellow Pear (Solanum lycopersicum 'Yellow Pear'): Known for its clusters of sweet, pear-shaped yellow tomatoes, this indeterminate variety dates back to the early 19th century.
- Green Zebra (Solanum lycopersicum 'Green Zebra'): A cross between four different heirloom tomatoes, this indeterminate "heirloom hybrid" is prized for its bright flavor and chartreuse color.
- Pink Brandywine (Solanum lycopersicum 'Brandywine'): This indeterminate, easy-to-grow heirloom offers hefty, flavorful fruits in a beautiful shade of blush.
- Celebrity (Solanum lycopersicum 'Celebrity'): Determinate Celebrity tomatoes are disease-resistant and prolific, with the added bonus that they fruit from the time plants reach their mature size until frost. But they don't keep growing larger as the season goes on as indeterminate tomatoes do.
Varieties of Tomatoes: Early, Mid-Season, and Late-Season
Another factor to consider when choosing tomato varieties is when fruits will mature. Early-season varieties will grow ripe, ready-to-harvest fruit in 42 to 70 days. Mid-season tomatoes mature in around 70 to 80 days, while late-season varieties take 80 to 110 days to mature.
Harvest tomatoes when fruits have fully colored, with a firm yet supple texture and healthy size for their variety. Ripe tomatoes will have smooth, shiny skin. Use scissors or pruners to cut stems when harvesting, as pulling fruits off can damage tomato plants. When a frost is forecast, remove all fruit from in-ground plants.
How to Grow Tomato Plants in Pots
Because they're more compact, determinate tomatoes (sometimes called bush tomatoes) are ideal for container planting, although there are some indeterminate types bred for planting in pots.
- Use a high-quality soilless potting mix that's light and drains well while holding onto necessary moisture. Mix in organic compost before planting to add fertility.
- Tomatoes planted in containers generally benefit from cages or other supports.
- Keep them well-watered as container plants dry out more quickly in hot weather than in-ground plants.
Pruning tomatoes can offer several benefits, like earlier harvests, disease resistance, and larger fruits. It's recommended to pinch or prune away the suckers—shoots that grow out of the axils where leaves meet stems—in indeterminate tomato varieties. This allows plants to direct energy towards fruiting rather than excess leaf growth and keeps plants tidier and generally easier to maintain. While determinate varieties are not always pruned, plants can develop stronger stems if you remove suckers that grow below the lowest flower.
Propagating Tomato Plants
You can use the suckers you remove from your tomatoes to propagate new plants. Here's how.
- Pinch or prune off a good-sized sucker from a mature tomato plant. Remove the leaves on the lower half of the sucker stem.
- Poke a hole in the soil nearby, leaving adequate space between plantings.
- Plant the sucker in the hole. Roots will grow along the portions of the sucker's stem below the soil line.
- When you see new growth, you'll know the sucker has rooted. You can leave it in place or dig it up and relocate it to another area of your garden.
- Care for the plant as usual.
How to Grow Tomato Plants From Seed
Start tomatoes from seed indoors six to eight weeks before your region's first frost date. Fill seed trays with soilless seed starting mix and moisten the soil well. Plant tomato seeds a quarter-inch deep and cover them with soil. Put the trays in a warm place under a grow light. When the seedlings are two to three inches tall, pot them up into three-inch pots, burying them up to the lowest leaves.
When the weather is warm enough, begin hardening off the seedlings by bringing them outdoors in the shade for a few hours each day, gradually increasing how much light they get and their time outdoors. Once night temperatures are consistently above 50 degrees, you can transplant tomato seedlings outside.
Common Pests and Plant Diseases
Tomatoes can fall prey to diseases and garden pests. Plant disease-resistant varieties and prevent issues with crop rotation, watering roots rather than leaves, cutting away low branches that might come into contact with soil, pruning, and giving plants adequate space.
Treat insects like aphids by spraying them off or treating plants with neem oil or horticultural soap. Some pests, like tomato hornworms, must be picked off by hand and killed to remove them from plants.
Do tomato plants need sun or shade?
Tomato plants require full sun to grow. Put them in a spot that gets at least eight to ten hours of direct sunlight per day.
How long do tomatoes take to grow?
Tomato plants take anywhere from 42 to 110 days, depending on the variety you choose and the climate in your region. Early varieties will have ripe fruit the soonest.
What are the best companion plants to grow with tomatoes?
Basil and marigolds are some of the most popular companion plants for tomatoes. A variety of herbs, flowers, and vegetables can help ward off pests, attract beneficial insects, and suppress weeds when planted alongside tomatoes.
Planting and Spacing. Utah State University Extension.
Growing tomatoes in home gardens. University of Minnesota Extension.
Keeping Tomatoes Healthy in Hot Weather. The Ohio State University.
Growing Tomatoes. Cornell Cooperative Extension.
Pollinating Tomatoes in High Tunnels. South Dakota State University Extension.
Pollination Problems of Tomato and Pepper. Missouri Botanical Garden.
Desuckering and Rooting Tomatoes. Clemson Cooperative Extension.