How to Grow Tomatoes: Planting, Growing, Harvesting
Tomatoes are one of the most popular vegetables in the world. Technically speaking, they’re a fruit, but that doesn’t stop them improving pretty much any dish they’re added to. They’re rich in vitamins and minerals, pack a sweet, umami flavor, and we’re sure that every gardener has at one point thought about growing tomatoes at home.
In this guide, we’ll reveal our best tips on how to grow tomatoes, starting with sowing the seeds, watering and fertilizing, pruning and staking, as well as harvesting tomatoes and storing them for later. We’ll also discuss how to grow tomatoes indoors, and whether it really is as difficult as beginner gardeners think.
Also known as bush tomatoes, these plants grow to a determined height of about 3 feet (1.2 meters), produce fruit that ripens at the same time, and usually only produce one crop per season. They don’t take up much space, don’t typically require staking, and are ideal for growing in containers. Popular varieties include:
- Roma tomato, which produces large fruit weighing up to 3 ounces (85 grams)
- San Marzano, a plum tomato variety that’s ideal for cooking
- Tiny Tim, a cherry tomato that matures in just 45 days
- Tumbler, a variety perfect for hanging baskets
Better known as vine tomatoes, these are taller varieties that can grow to a height of almost 6 feet (1.8 meters). They will need a cage or trellis, and are better suited for outdoor gardening, where they have plenty of space to spread out.
An indeterminate tomato plant will produce fruit throughout the growing season and will have a higher tomato yield per plant, but will take longer to reach maturity. Cherry tomatoes are the best-known example of indeterminate varieties, but other popular cultivars include:
- Beefsteak tomato, which produces large, juicy, fleshy fruit.
- Brandywine, an heirloom variety with large fruits and excellent flavor.
- Momotaro, a Japanese hybrid with large, pink, and very sweet fruit.
When to Start Growing Tomatoes From Seed
Tomatoes are a warm-season crop. Young tomato plants are particularly sensitive to cold snaps, so always wait at least a month after the last frost has passed before sowing. For best results, plant tomatoes outdoors in late spring or early summer. In warm climates, such as USDA hardiness zones 10 to 12, you can even grow tomatoes as a fall and winter crop.
The ideal temperature for growing tomatoes is between 55 and 85°F (13 to 29°C). Although these plants love heat, they will struggle to grow in temperatures over 86°F (30°C). And once the thermometer hits 95°F (35°C), they will not only fail to set fruit but any tomatoes you have on the vine will stop ripening. You can use our planting calendar to check when is the best time to plant tomatoes in your growing zone.
Depending on how early you want to start your tomato growing season, you have two options.
Starting Tomatoes Indoors
This is a great choice if you live in a cooler climate, with long winters and late springs. Sow tomato seeds indoors at least two weeks before the last frost. Take a few compostable seedling pots, fill them with quality potting soil, and plant one seed per pot. When the young plants are at least 2 inches tall (5 cm), you can simply plant the entire pot in the soil. Using compostable pots for your tomato plants means there’s no risk of damaging the root ball, which greatly reduces transplant shock.
Sowing Tomato Seeds Outdoors
You can start growing tomatoes from seeds outdoors when the soil temperature is at least 55°F (13°C). Tomato seeds can tolerate soil temperatures as low as 50°F (10°C), but they will take longer to germinate. You can use row covers, or even a cardboard box, to protect the seedlings during chilly nights.
Where to Grow Tomatoes
Tomato plants need full sun to grow. That means at least 6 hours of direct sunlight per day. Tomatoes can tolerate some partial shade, but they will grow slower and will produce a smaller yield.
In terms of planting site, tomatoes are fairly adaptable. As long as they receive plenty of sun and are growing in rich, moist soil, they’ll be happy in garden beds, straw bales, hanging baskets, and even upside-down containers. In cooler climates, or in areas that don’t have at least 4 months of warm, sunny weather, growing tomatoes in a greenhouse or maybe a hoop house is the best alternative.
How to Plant and Grow Tomatoes
Tomatoes can be easy to grow if you plan everything carefully. Here are the best conditions for growing tomatoes in your vegetable garden:
- Full sun
- Rich, well-draining soil
- Regular watering
- Excellent air circulation
With that in mind, let’s take a closer look at everything you need to know about how to grow tomatoes from seed.
Prepare the Soil
Tomatoes can grow in pretty much any garden soil but will perform better in a loamy, well-draining, nutrient-rich mix. The soil pH for growing tomatoes can be as low as 5.5 and as high as 7.5. These plants prefer acid soil, but avoid anything below 5.5. When in doubt, use a soil test kit, and lime the soil if the pH is too low.
For a successful harvest, prepare the soil for tomatoes 8 weeks before the planting date. Dig up the soil to a depth of one foot (30 cm) and mix in plenty of compost or well-rotted manure. If your plan is to sow seeds directly in the soil, cover the plot with a black, thick plastic tarp. This will help the soil warm up, which means the seeds will germinate faster.
Sow Tomato Seeds
Always wait at least four weeks after the last frost has passed before sowing tomato seeds outdoors. Once soil temperature is at least 55°F (13°C), sow seeds half an inch deep in a sunny part of your garden, and water them well. Keep rows at least 4 feet apart (1.2 meters), to ensure excellent air circulation.
If the soil is warm enough, tomato seeds can germinate in as little as 5 days. Otherwise, the seeds will take 7 to 10 days to sprout. Once the seedlings have at least one pair of true leaves, you can thin them out by gently pulling the weaker ones out of the soil. For determinate tomato varieties, the ideal spacing is about 2 feet apart (60 cm). For indeterminate types, leave 3 feet (90 cm) between each plant.
Transplanting Tomato Seedlings
If you live in a cooler climate, you can either start your tomatoes indoors or buy tomato seedlings from your local garden center. Wait until nighttime temperatures are at least 50°F (10°C) before transplanting them to the garden soil. In the meantime, you can harden off your tomatoes by taking them out for a few hours each day, gradually exposing them to more sun.
Transplant your tomato seedlings gently and carefully, to avoid damaging the roots. If you’re using compostable seed starter pots, your job will be made infinitely easier. Dig a hole using a garden trowel and plant the seedlings as deeply as possible, until the bottom leaves are just above the soil level. Tomatoes grow adventitious roots from the buried stem, and by adding more soil around the young plants’ stem, they will develop a strong root system.
Unless you’re growing them in hanging baskets, all tomato varieties need some form of support. This will prevent the stems from snapping under the weight of the fruit, and will also keep the ripening tomatoes off the ground and away from pests. Determinate varieties require less work, but indeterminate tomatoes tend to grow tall and spread out, and will need a tall, sturdy support.
Set your supports in place soon after thinning or transplanting your tomatoes, to avoid disturbing the plants’ roots. For determinate varieties, use a bamboo or plastic stake at least 5 feet tall (1.5 meters), and hammer it into the soil to the depth of one foot. Use soft string to tie the plant to the stake. For indeterminate types, you can use a long stake, a cage or even a tomato trellis. Use a piece of string that’s strong enough to support the weight of the plant but soft enough to not cut into the stem, and tie the tomato vine to its support as it grows.
Prune your tomatoes regularly. This will help keep their shape, encourage them to produce more fruit, and also minimize the risk of fungal disease by improving air circulation. Always use a sharp pair of gardening scissors to prune your tomatoes, and never prune them when the stems and leaves are wet.
All tomato varieties benefit from pruning the leaves growing at the base of the stem, as well as pinching suckers. Suckers are small shoots sprouting from where the tomato branch joins the main stem. In time, they can grow into actual stems, but in doing so, they will draw energy from the main plant, which will result in a smaller yield. Trim the suckers as soon as they appear, and keep the bottom 12 inches (30 cm) of the tomato stem bare of leaves.
The secret to growing tomatoes successfully is correct watering. These plants love moist soil but are also sensitive to overwatering. They will also need more water as they start setting fruit, but will grow sweeter fruit if they receive less water when they begin to ripen. Finding the right balance may be tricky, but it’s essential. In fact, inconsistent watering is usually the main reason why tomatoes split or develop blossom end rot.
Water your tomatoes slowly, deeply, and regularly. The easiest method is to install a drip irrigation system with a timer and run it for an hour or so in the morning. This will ensure that the tomatoes receive enough water, and also reduces the risk of powdery mildew by not getting the leaves wet. When the plants are at least 4 inches tall (10 cm), add some mulch or straw around the base to help the soil retain moisture.
Tomatoes are heavy feeders. Ideally, you should plant them in soil that has been amended with plenty of compost. Otherwise, give them some fertilizer soon after planting. When they start setting fruit, feed them once every 2 to 3 weeks.
The best tomato fertilizer should be high in phosphorus and potassium, to encourage them to produce more fruit. Avoid giving your plants too much nitrogen, as this will encourage leafy growth and fewer tomatoes. Organic fertilizers such as fish emulsion or worm castings tea are a good choice, or you can buy a ready-made fertilizer for tomatoes.
How to Harvest and Store Tomatoes
Depending on the variety, tomatoes can take between 60 and 100 days to mature. Determinate tomatoes produce only one crop that ripens all at once. Meanwhile, indeterminate tomatoes will continue to produce fruit until late fall and will ripen in several batches.
Use a sharp pair of gardening scissors to cut the tomatoes off the vine, and leave the green stem or peduncle attached to the fruit. This will help them keep longer after harvesting. If you have green tomatoes on your vines by the time the first frost hits, simply cut down the entire plant and hang the vines in a garage or cellar, until the tomatoes ripen. You can also put unripe tomatoes in a paper bag with a banana, and they will ripen faster.
After harvesting tomatoes from your garden, you can either eat them fresh or store them for later. Ripe tomatoes should be stored upside down in an open container, on paper towels. The best place to store them is in a warm, dry, airy room, such as a pantry, or even just a top shelf.
You can also keep tomatoes in the fridge for a week or so, but storing them in the open allows them to continue ripening, which improves their flavor. If you have a large tomato harvest, you can freeze it, can it, or turn it into tomato paste.
Common Tomato Pests and Diseases
Most tomato plant problems are caused by two things: high humidity and poor air circulation. If your garden lacks the right growing conditions, your tomatoes will suffer, even if you’re planting disease-resistant varieties. The most common tomato diseases include:
You can treat powdery mildew by trimming infected leaves and spraying the leaves with a sulfur-based organic fungicide spray. Unfortunately, most viral and fungal diseases, such as mosaic virus and fusarium wilt, have no cure. Your only choice will be to pull out and burn your sick tomato plants.
Tomatoes are also susceptible to blossom end rot, which causes the bottom of the tomato fruit to develop brown, sunken spots. Blossom end rot is the result of calcium deficiency in the fruit and is caused by irregular watering, a buildup of fertilizer salts in the soil, too much nitrogen, or damaged plant roots.
Common tomato pests include aphids, caterpillars, stinkbugs, and tomato hornworms. Check your plants daily and remove any tomato leaves turning yellow or damaged by pests. Spray the plants with an insecticidal soap solution, hand-pick pests such as worms and caterpillars and drop them in a bucket of soapy water.
Companion Planting With Tomatoes
If you’re not sure what to plant with tomatoes, think of the ingredients for a bolognese sauce. Carrots, celery, onion, garlic, and herbs such as parsley, oregano and basil are all excellent tomato companion plants. Another option is to think of what you’d put in a salad, such as lettuce, radishes, chives, and edible flowers such as nasturtiums. And if you have a greenhouse or hoop house, try to make the most of your space by growing tomatoes and cucumbers together.
How to Grow Tomatoes in Containers
Growing tomatoes in pots is a great solution if your garden has poor soil, lacks space, or if you simply want to grow tomatoes indoors. There are, however, two essential tips to keep in mind: picking the right varieties, and knowing how to space them.
The best tomatoes for container growth are determinate tomatoes or dwarf varieties. They take up less space, mature faster, and are easier to harvest. If you’re up for a challenge, you can also try growing indeterminate varieties such as cherry tomatoes, but remember that they can grow up to 6 feet tall (1.8 meters) and will need a cage or trellis.
Another common mistake to avoid is planting two or three plants in the same pot. Tomatoes need space to grow healthy roots, so if you’re wondering how many tomato plants per pot you should have, the answer is one.
To plant tomatoes in pots, pick a 12-inch or 5-gallon container with drainage holes and fill it with a loose, organic potting mix. You can either sow 2 to 3 tomato seeds per container and thin them after they sprout, or buy seedlings from a local nursery and plant one in each pot. Put the container in a sunny spot, keep the soil moist, and fertilize your tomatoes once every 2 weeks once the fruit begins to set.
How to Grow Cherry Tomatoes in Pots
Everyone loves cherry tomatoes, so trying to grow them in containers is very tempting. The downside is that most cherry tomato varieties are indeterminate, which means that they take up a lot of space and require more work. Here are a few tips to make growing them easier.
- Pick a determinate cherry tomato variety such as Tiny Tim, Cherry Falls, or Patio Choice Yellow.
- Always use a large pot with drainage holes at the bottom, and use a moisture-retentive but well-draining potting mix. Tomatoes growing in containers can be very sensitive to root rot.
- Never plant more than one tomato plant per pot, otherwise, it won’t develop properly and will produce a small yield.
- Provide your cherry tomatoes with stakes or a trellis. Or, to keep things really simple, grow them in hanging baskets.
Growing Tomatoes Indoors
One of the main reasons you rarely find tomatoes listed among the best vegetables to grow indoors is because, honestly, they don’t grow that well indoors. Of course, you can plant them in a container, and if you keep them in a warm window, water and fertilize regularly, your plants will grow. But even gardeners with a green thumb will struggle with them because most homes lack two crucial growing conditions needed to keep tomato plants happy: proper light and good air circulation.
Let’s talk about light. Tomatoes need full sun, and that’s not up for negotiation. Admittedly, they can grow in partial shade, but indoor partial shade is significantly darker than a shaded corner in an outdoor garden.
Unless your tomato plants receive at least 6 hours of direct sunlight per day, they will grow leggy stems, lots of leaves, and maybe a few clusters of flowers that, if you’re lucky, will set fruit. The easiest way to prevent that is to keep your tomatoes in a room with southern exposure or invest in a set of grow lights.
Good Air Circulation
Air circulation is also essential. It reduces the risk of fungal disease and, most importantly, helps fruit production. Tomatoes are self-pollinating, but in a room with stagnant air and high humidity, the pollen will clump, and the flowers will drop before they’re pollinated. This is also a common problem when growing tomatoes in a greenhouse or hoop house.
You can prevent problems with pollination by using an oscillating fan for plants and keeping it on for a few hours each day, or by using an electric cordless tomato pollinator.
Tomatoes are one of the most tempting yet intimidating vegetables to grow. In fact, many beginner gardeners shy away from them because they worry they won’t give their tomatoes the right growing conditions. But with our comprehensive grow guide, you’ll be set for success. And once you get the hang of it, you’ll find yourself adding tomatoes to your garden planner year after year.
More Growing Guides
Interested in growing more vegetables? Then check out our list of easy vegetables for your garden or jump directly to our in-depth growing guides!