this article, gardening expert and farm owner Taylor Sievers examines how to plant, grow, and care for tomatoes in your garden this growing season.

Would it be summertime without the image of bright red tomatoes piled high on country roadside stands and farmer’s market tables? Do you dream of harvesting your very own juicy, freshly-sliced tomato for your BLT sandwich? Are you looking for a sweet or tart snack that’s easy to pluck and pop in your mouth as you stroll through your backyard? If all this sounds wonderful, then I’d venture to say it’s time to step into the world of growing delicious tomatoes!

Tomatoes, scientifically known as Solanum lycopersicum, are members of the Solanaceae family, also known as the nightshade family. The nightshade family includes popular garden plants such as eggplant, peppers, and potatoes. Other not-so-friendly alkaloid-producing plants this family includes are henbane, Jimson weed, belladonna, and tobacco. In fact, because of the bad rap of some of the plants in this family, the tomato was once thought to be poisonous, but we’ll talk more about that later.

Tomatoes are grown as an annual, though in the tropics they can be grown as a perennial. They have soft, hairy stems and leaves. The leaves are often lobed, and the entire plant has a very distinct scent. The flowers are typically yellow. After pollination becomes round or plum-shaped fruit in colors varying in shades of green, yellow, orange, pink, red, and purple! Read on to learn more about the tomato’s interesting history, growth habits, uses, and awesome health benefits!
Plant History and Cultivation

All cultivated varieties of the tomato today are derived from the species Solanum lycopersicum. Wild relatives of this species are native to the coastal areas of South America from Ecuador down to northern Chile.

The small, red, cherry-tomato-like fruits were cultivated by South Americans and eventually spread up into central America possibly by humans, birds, and other natural routes. Around 7,000 years ago, these smaller-fruited, often weedy-in-nature, plants became domesticated and gave rise to the more modern-looking tomato.

Just like many plant species of the Americas, interest in tomatoes was piqued again after Columbus’ travels to America. This occured when Spanish explorers brought plants back with them to Spain. In Spain, the tomato was dubbed “pome dei Moro” or “Moorish apple.”

The first written appearance of the tomato was in Italy in 1544, where the tomato was called “pomo d’oro” or “golden apple.” This reference to a golden color indicates that possibly the varieties that made their way to Europe initially were yellow, rather than red.

Because the plants were members of the nightshade family, a family known for poisonous plants, people were wary about eating them. In fact, the tomato was thought of more as an ornamental plant at first because of its nightshade family relation. The French called the tomato “pomme d’amour” or “love apple.”

Tomato Popularity Grows in the States
Finally, in 1781, we find records of the tomato being grown in Thomas Jefferson’s garden. It is also suggested that the tomato came up with a refugee from Santo Domingo in 1789. It was then introduced to Philadelphia, and then in 1801, the tomato was introduced by an Italian painter to Salem, Massachusetts.

Tomatoes were used as food in New Orleans by 1812. This was doubtless because of the heavy French influence on southern cuisine, with dishes such as gumbo and jambalaya. However, in the northeastern United States, the tomato was still mostly thought of as poisonous or, at the very least, suspicious. In 1820, a man named Colonel Robert Johnson stood on the courthouse steps of Salem, New Jersey, and ate a raw tomato to prove that the fruit was edible!

By 1850, tomatoes could be found at urban markets and were widely grown in American home gardens. There were still suspicions about their edibility. Some cookbooks would suggest “cooking for three hours or more” to get rid of the “raw taste.”

Fruit or Vegetable?
Though botanically speaking tomatoes are a fruit, in 1893 the U.S. Supreme Court ruled that the tomato is a vegetable for “tax purposes.” This was due to the tariff act of 1883 which placed a 10% tax on any “vegetables in their natural state” that were imported. Vegetables that were “green, ripened or dried” could enter tax-free. While the importers argued then that tomatoes were technically a fruit, their plea was dismissed.

Tomatoes Today
By the late 19th century, tomatoes were considered edible. They were widely grown and distributed, however, there were reports that tomatoes could cause cancer. Remarkably, the converse was actually found to be true because tomatoes contain high amounts of lycopene. Lycopene is an antioxidant correlated with decreased risk of cancer in the digestive tract, cervix, prostate, and pancreas.

Today, tomatoes are widely cultivated across the world and in the United States. The average U.S. citizen consumed 19.32 pounds of tomatoes in 2020. Tomatoes are the second most consumed “vegetable” in the U.S. behind potatoes. Two main sectors exist in tomato production: fresh market tomatoes and processed tomatoes (canned tomato products, tomato sauces, and tomato pastes).

Florida and California tomato production comprise about ⅔ of the total U.S. fresh tomato acreage. Greenhouse and unheated plastic tunnel production of tomatoes have helped growers in temperate climates extend their production seasons. These systems have also helped farmers increase the quality, consistency, and yields of tomato fruits harvested.

Tomato Propagation
You will likely be either growing your tomatoes from seed or purchasing transplants at a retail store when growing them in the home garden. Tomatoes can also be propagated by cuttings. However, there are few reasons to propagate tomatoes in that manner for a home gardener.

Commercial growers may use grafted seedlings, where the stem of the tomato plant is grafted (attached and grown) onto a different variety’s roots. This is a complicated process that, again, the home gardener will likely not need to worry about as they start their tomato growing journey.

Seed Starting
To start tomato seed, you will get the best results if you start your seed indoors around 4 to 6 weeks prior to your last estimated frost. These plants are highly frost-sensitive, so don’t be in too much of a hurry to get them outside.

Sow the seeds at a depth of ¼ inch in a cell propagation tray, pot, or open flat filled with seed-starting mix. Tomatoes love heat. So, if you can purchase a seedling heat mat and set it to 75 to 85⁰F, you will have better and more even germination. Bump the heat mat temperature down to 70⁰F after emergence and provide bright light for your seedlings.

Keep the seedlings moist but not soggy. Make sure to monitor moisture levels more often if you are using heat mats.

If you are not using heat mats to start your seeds, then make sure to put them in a warm, well-lit place. Sometimes people will start seedlings on the top of their refrigerator because of the warmth that exudes from there. Whatever the case, make sure you do not place your seedlings directly in front of a blowing heat source, like an air vent, because this will dry your trays and seedlings out quickly.

Make sure your seedlings have a bright overhead light. Too little light and the seedlings will be elongated with smaller leaves and tend to flop over (a term known as etiolation). In cases with severely reduced light, the plant will turn yellow (chlorotic).

When to Plant Tomatoes
If you plan to direct sow your tomato seedlings into the garden, make sure to sow at ¼ inch depth after your last estimated frost or when the soil has warmed to at least 60⁰F.

If you started your tomato seeds inside, when tomato seedlings are about 5 inches tall, you can begin to harden them off so that they have better chances of surviving outside. The first part of hardening off is reducing the amount of water you give them. Then, once the last estimated frost date has passed, you can begin to set the seedlings outside for periods of time during the day.

Make sure that you keep your seedlings in an area that is shadier. It should be an area that’s not exposed to lots of wind. They will not be used to the bright sun at first and may become scalded. Their stems will likely not be strong enough to withstand too much wind either.

Increase the time they’re outside over a period of a week to two weeks until you’re ready to transplant them into the garden or into a container for your patio. If night temperatures are still below freezing, then make sure to bring your plants inside at night.

How to Grow Tomatoes
Transplant your seedlings into an area of the garden that receives full sun (6 to 8 hours of direct sunlight). The best time to plant transplants is in the late afternoon or evening. This is so the plants have time to get adjusted in the cool temperatures of the evening and night before intense heat sets in the next day.

Most tomato plants are vining in nature (though some varieties are bushier). This means planting them at least 18 to 24 inches apart in the row and 36 inches apart between rows. Standard practice is to use tomato trellises, stakes, or cages to keep the stems and fruit from trailing along the ground. This will help reduce the incidence of disease and overall keep your tomato plants looking tidier.

What’s neat about tomatoes is that if you bury their stems, the stems will produce roots! The more roots your plant has, then the higher likelihood that the plant will be healthier and more vigorous. If you are purchasing tomato seedlings that are quite leggy (or your own starts are very tall with a lot of space between the soil and the first set of leaves), then utilize this characteristic of the tomato!

Plant your seedlings deeper so that most of the stem is buried below the first set of leaves. You may even pluck off the lower leaves and bury that node in the soil. This practice will help a leggy seedling because it will be less likely to flop over. You’ll also have a bonus of hopefully more root production below the soil surface.

Crop Rotation
An important note about tomatoes is that you should practice crop rotation within your garden! Do not plant tomatoes in areas that have been previously cropped to other nightshade family plants like peppers, eggplant, and potatoes!

Rotate your crops in your garden each year. You want to make sure that you do not have the same family of plants in the same spot. If you do, you may end up with a buildup of pest and disease issues. Crop rotation helps break up the pest and disease cycles.

Water
Make sure that tomatoes are receiving consistent moisture during growth. Tomatoes need 1 inch of rainfall per week in order to thrive. If you have to water your tomatoes, make sure that you water well, encouraging the water to go deep within the soil rather than just a shallow sprinkling on the surface that will only encourage rooting at the soil surface.

For reference, 1 inch of water will wet sandy soil down to a depth of 10 inches and in clay soil 1 inch of water will wet the soil down to 6 inches. You can use a trowel or your finger to check the moisture level of the soil. If soil is only moist down to the first few inches after you’ve watered, then you need to water more.

If you choose to plant in containers, make sure that the container is at least 12 inches deep or more. You do not want to restrict root growth, so a bigger container is better. The advantage of container growing is that it can be easier to trellis the plants and the roots will often be warmed more than if they were in the ground if you’re trying to get them growing early.

Fertilizer
Fertilizers are often sold by their percentages of nitrogen, phosphorus, and potassium (N-P-K) on the package. A well-balanced fertilizer will have mostly equal parts of N, P, and K, and low nitrogen fertilizer will have a smaller first number (N) than the second two numbers (P, K). Too much nitrogen will promote more leafy growth and less fruit growth.

To promote good soil structure and soil fertility, you can add well-rotted manure or compost to your soil before planting. Use a high quality compost, or even create your own mixed with spent fruits, vegetables, coffee grounds, and other items. Just be aware your tomato plants may need additional fertilizer other than the manure or compost, whether you choose to use synthetic or organic fertilizer.

If you wish to apply a foliar fertilizer, make sure the fertilizer is for foliar use (spraying on the leaves versus applying in the soil). You will burn the leaves of your plants if you use fertilizer as a foliar spray that was not intended for foliar use. Some people will use a foliar calcium fertilizer if they begin to have issues with diseases like blossom-end rot that are exacerbated by calcium deficiencies.

Maintenance
There is debate on whether you should prune your tomato plants or leave them unpruned in order to receive good yields. Side shoots, known as “suckers,” will often grow at the axil between a leaf branch and the main stem. You may prune or pinch out these suckers for several reasons such as:

Reducing incidence of disease due to increased air flow
Earlier and/or prolonged harvest
Larger fruits
Reduces the total weight of the plant, so less support may be needed
However, pruning will reduce the number of leaves per plant, and thus will decrease the amount of photosynthesis potential. The amount of fruit per plant may be reduced, and due to fewer leaves, the fruit may be more susceptible to sunscald.