This is the story of an edible which evolved from a horticultural villain into a hero, the star of the vegetable garden. It’s hard to believe but I’m talking about the tomato, which was once known as the “poison apple,” Today the tomato is arguably the most popular plant in the vegetable garden, and often grown even by non- vegetable gardeners in the side yard, beside the house, or even in pots on patios, decks, and even in hanging planters.
I don’t think summer would be complete without tasting the sun from a vine-ripened tomato, plucked fresh from the garden. Today we eat the versatile tomato raw, like an apple, on sandwiches, in salads, in soups, juiced, in sauces, grilled or stewed. It would be hard to imagine any home garden that did not have a few tomato plants. Today, tomatoes are considered by many to be the most prized vegetable in the garden. But, the history of the tomato reveals that this was not always the case,. This wonderful taste of summer was for over 200 years thought of as a poison apple and grown only as an ornamental plant!
The tomato originated here in the Americas, and in the early 16th century, Spanish conquistadors returning from Mexico were thought to have first introduced the seeds in southern Europe. Some researchers credit Cortez with bringing the seeds to Europe in 1519. The perception that tomatoes were poisonous may have arisen because the plant belongs to the Nightshade plant family — of which some species are indeed poisonous. A second reason that is often cited is that when aristocrats ate tomatoes, they become ill and often died, but this was a case of misplaced blame because wealthy Europeans often used pewter plates that had a high content of lead. Tomatoes, being high in acid, would leach lead from the pewter plate, resulting in illness or even death by lead poisoning.
The legal profession then added its own twist to the saga of the tomato. Many gardeners think of the tomato as a vegetable but technically (botanically) it is a fruit. This confusion may have arisen because tomatoes are often used in the kitchen as a vegetable. In 1893, the United States Supreme Court, in the case of Nix vs Hedden , unanimously ruled that a tomato should be taxed as a vegetable rather than a fruit (lower tax rate on fruit), because it was used in the kitchen as a vegetable; therefore, it should be taxed as a vegetable. Thus, in the minds of many, the tomato became a vegetable.
May is the month that the gardener carefully transplants tomato plants into the garden and begins the long wait to savor that first homegrown tomato taste.
But before we can transplant those tomato plants into the garden, we must wait until the danger of frost has passed, which in our area in Central Virginia is May 15th. Many of my conservative gardening friends wait a full week after the final frost date; they know that May 15th is only the average last frost date. Tomatoes are warm season plants that grow best at temperatures of 70-80 degrees F.
Choose a sunny location as tomatoes require at least 8 hours of sunlight each day.
Tomatoes prefer soil that is well drained and amended heavily with organic matter. Decomposed manures, compost, peat or other humus can be tilled into the garden site as soon as the soils can be worked in the spring.
Tomatoes require a soil with a pH around 6.5. The pH is the general measurement of acidity in the soil. A soil test is the best way to determine the pH of your tomato patch. Soil testing kits can be obtained through your local county extension office. If the pH of the soil is too low or acid, add dolomitic limestone in accordance with the soil test recommendations. In addition to adjusting the pH, dolomitic limestone also provides calcium and magnesium, both important elements for the growth and health of the tomato plants. If possible it is recommended that lime be applied several months before planting to allow time for the lime to react with the soil and adjust the pH. Additional soil testing information can also be obtained from the Virginia Cooperative Extension Publication 452-125.
As with any gardening activity, a little planning will often provide that edge in growing a successful tomato crop. In deciding what tomato varieties you want to plant, think about your goal. Is your goal to have the first ripe tomato in the neighborhood? Or do you wish to produce an adequate crop for eating thoughout the season? Or perhaps you want even more tomatoes — enough not only for summer eating but also for preserving, i.e., canning, making juice, salsa, and sauces. With your goal in mind, you can decide how much room to allocate to tomatoes — how large a garden footprint to dedicate to growing tomatoes. A general rule of thumb is that a healthy tomato plant can produce 10-15 pounds of tomatoes over the growing season and will require approximately 3 square feet of space.
The varieties of tomatoes range in the hundreds and can often be overwhelming to a new gardener: gather information from gardening friends for their favorites, the varieties that dwell in our area. Another source of information for selecting tomato varieties is found in Virginia Cooperative Extension Publication 426-480, an article titled “Vegetables Recommended for Virginia.” Also, it is helpful to keep a journal and make notes on which varieties performed well — and which did not — to be used in selecting future varieties.
Tomatoes varieties are differentiated by plant characteristics and fruit characteristics. Plant characteristics are used to describe the plant, whereas fruit characteristics are terms used to describe the fruit size and color. Following is a brief overview of these two characteristics:
Tomatoes based on plant characteristics:
- Midget, patio or dwarf tomato plants are very compact vines that are usually grown in containers or hanging planters. The tomatoes produced by these types or plants are often cherry tomatoes but not always. These plants are usually short lived, producing their crop quickly and for a short period.
- Determinate or Compact tomato plants have a compact bush form and produce most of their crop at one time. A determinate plant will produce tomatoes for two to five harvests. In Virginia a determinate plant will not produce tomatoes throughout the summer. Determinate types ripen their fruit over a short period of time, so successive plantings may be desirable to keep the harvest coming through the entire season, The short ripening period of all the fruit is a trait that facilitates harvesting for large producers, so many determinate varieties were developed by tomato processing companies. Similarly, determinate plants are often the choice of the gardener who wants a large supply of ripe fruit at once for canning.
- Indeterminate varieties set fruit clusters along the vine stem that continues to grow all season. They will continue to produce fruit, if harvested throughout the season, until the first frost or disease kills the vine. This is the type of all- season tomatoes that most vegetable gardeners like to grow. Indeterminate plants perform best when provided some type of support such as stakes or wire cages. The supports keep the fruit from contacting the soil, helping to prevent fruit rot.
Tomato Types based on fruit characteristics:
- Cherry tomatoes have small, cherry-sized fruits — usually about 1-inch diameter — that are usually grown to be eaten in salads. Plant size can vary from dwarf to seven-footers depending on the variety. Cherry tomatoes are generally sweeter than the larger types. The dwarf or compact plant varieties are ideal for containers. Cherry tomato plants are often heavy producers, so one or two plants are usually sufficient for the home garden.
- Standard Tomatoes usually are smooth and round, and are larger in size than cherry tomatoes. Also called slicing or main season tomatoes, this group includes well known cultivars such as Better Boy, Celebrity, Early Girl and Rutgers.
- Beefsteak types are large fruit types, sometimes weighing as much as two pounds or more. These cultivars are usually late to ripen; home gardeners often plant some standard or early tomatoes for early harvest.
- Paste (Roma type) tomatoes have a pear or elongated shape with a thick, somewhat dry flesh with few seeds. Paste tomatoes are less juicy than standard or beefsteak tomatoes. Paste tomatoes are a favorite for processing into sauces and tomato paste and for canning since they do not need to be cut, and because they are meatier than standard tomatoes, they are often canned whole.
- Colors — yes, tomatoes come in many colors other than red — yellow, orange, yellow, dark reddish purple, green and striped. Many specific colors are heritage or heirloom varieties. Tests have shown there is no correlation between color and the acidity of tomatoes.
Most gardeners want to maximize the tomato harvest season, and the time period between planting and harvesting can vary greatly. Most seed packets and catalogs indicate the a number of “days to harvest” for individual tomato varieties. In general, days to harvest is the number of days from the time the transplants are planted in the garden until one can expect ripe fruit from that individual tomato variety. For example, the days to harvest for the Early Girl variety is 57 days; for the Better Boy variety, it is 75 days, while for the Pineapple variety it is 85-90 days. By planting different varieties with different days to harvest, the gardener can plan a longer harvest season. Remember that days to harvest is only an estimate, and may vary greatly from year to year. That’s because tomatoes are heat-loving plants, and the ripening of fruit may be slowed down by a string of overcast days, or prolonged cool spells. Thus, the days to harvest is a very soft estimate.1
Hybrid and Heirloom tomatoes:
Hybrids- Many tomatoes on the market today are hybrid tomatoes. A hybrid is the result of crossing two different plant varieties with the goal of combining the attributes of the parent plants and possibly obtaining more favorable traits than either of the parents. Many hybrids are bred to be disease resistant, produce good fruit size and shape, and increased yields.
Many new hybrid cultivars are resistant to or tolerant of some tomato diseases. This is indicated by a letter or combination of letters following the tomato name, such as F (Fusarium Wilts Race 1), As (Early Blight), FF (Fusarium Wilt Race 1 and Race 2), B (Bacterial speck Pseudomonas), N (Root-knot Nematodes), L (Septoria leaf spot), T (Tobacco Mosaic Virus), St (Stemphylium Gray leaf spot), A (Alternaria Stem Canker/Crown Wilt).
Heirloom– Increasing in popularity today are heirloom tomatoes. The definition of an heirloom tomato varies, but the term usually refers to an “open pollinated” variety that was in cultivation prior to 1940, when the first hybrid cultivars become available. Often heirlooms have been passed down within families or communities for many years, with seed saved from the best plants each year. All heirlooms are open pollinated. Open pollinated plants, when isolated from other tomato varieties, will grow true seeds each year and their seed can be saved with the expectation of the same plant and fruit quality each year.
Although open-pollinated heirloom cultivars have become very popular, many have little genetic resistance to common diseases and in general are not as productive as hybrid cultivars.
Planting Tomato Plants:
When you are selecting plants to be transplanted into the ground, select plants that have a fat stem and are about 6 to 10 inches tall. Unlike many vegetable plants, tomato plants should be planted deep. To do this, first gently remove all but the top two or three sets of leaves from the stem. The hole should be dug deep enough so only the remaining leaves on the stem are above ground. If the transplant is leggy, remove all the leaves except the top two or three true leaves and plant the stem horizontally. Roots will form along the stem, producing a stronger plant. Do not remove the plant from the container if the container is paper or a peat pot. Remove only the top inch from the container and make sure the pot is buried below the surface of the soil, to prevent the container from wicking away water from the plant. If the transplant is in a non-biodegradable plastic container, gently remove the plant from the container before planting; gently loosen the roots. Once the transplant is in the hole, press the soil firmly around the transplant so that a slight depression is formed for holding water. Pour approximately one pint of starter solution or diluted fish emulsion around each plant to wash the soil around the roots. Mulch with leaves, or straw around the tomato plant to maintain moisture and control weeds.
Take your time with harvesting. It’s often tempting to pick a tomato that is just starting to turn and bring it in the house to finish ripening on the window sill, but a perfect ripe home grown tomato eaten sun warm is unrecognizable from those eaten from the window sill or purchased from the local store.
Happy tomato-growing, and please join us in The Garden Shed next month for our article on tomato pests and diseases.
1 Dubose, Fred, The Total Tomato, Harper & Row (1985).
“Tomatoes,” Virginian Cooperative Extension Publication 426-418. http://pubs.ext.vt.edu/426/426-418/426-418_pdf.pdf
“Vegetable Planting Guide and Recommended Planting Dates,” Virginia Cooperative Extension Publication 426-431. http://pubs.ext.vt.edu/426/426-331/426-331.html
Smith, Annabelle, “Why the Tomato Was Feared in Europe for More Than 200 Years,” Smithsonian (June 2013). http://www.smithsonianmag.com/arts-culture/why-the-tomato-was-feared-in-europe-for-more-than-200-years-863735/
Howard, Doreen G., Heirloom Flavor:Yesterday’s Best Tasting Vegetables, Fruits and Herbs, For Today’s Cook, Cool Springs Press (2013). http://books.google.com/books?id=kEXuuSFzj2kC&pg=PA12&dq=tomatoes+AND+pewter+plates&hl=en&sa=X&ei=p0y3UdTQG4aJjALI44GgDQ&ved=0CFEQ6AEwBA#v=onepage&q=tomatoes AND pewter pl&f=false.
Polomski, Bob, “Tomato: Fruit or Vegetable?” Clemson University. http://www.clemson.edu/cafls/safes/faculty_staff/images/Tomato_Fruitorvegetable.pdf
Goldman, Amy, The Heirloom Tomato: From Garden to Table, Bloomsbury (2008).