By Bjorn Bergman
9 minute read
You’re in your garden or field, and you come across the perfect tomato. You take a look at the plant, the fruit, and you put it in your mouth. Then, you close your eyes. A flavor explosion ensues. Before you open your eyes, take a moment to put words to this perfection. What is it that makes this plant, this fruit, so good?
We can all agree that out of season, shipped-from-a-long-distance tomatoes will never make it to tomato perfection. These tomatoes are flavorless and anemic – not even close to the best tomato. The best tomatoes are the ones grown in our gardens and on our farms. They are picked at the peak of ripeness and eaten soon after harvest. But even when we grow tomatoes locally, we’re not guaranteed success.
With somewhere near 5,500 different varieties of tomatoes commercially available today how can you pick the one that’s just right for you?
A brief history of tomatoes
How did tomatoes end up in our gardens, on our farms, and on our plates? Tomatoes are native to Central and South America, where they grow wild. Researchers believe that a mutation in the small wild two-chambered tomato resulted in larger, multi-chambered tomatoes. Native farmers in Central America nurtured these new and improved tomatoes. The Aztecs named the plant xitomatl, or large tomatl.
The spread from Central and South America to the rest of the world is a bit murky, but what is clear is that European colonists were largely responsible for the spread of tomatoes around the globe during the 1500s and 1600s. As tomatoes spread more widely in the world, different cultures adopted them at different rates. Interestingly, prior to the 1900s, many Europeans and Americans thought tomatoes were poisonous, and should only be used as an ornamental garden plant.
The breeding work of Alexander Livingston significantly impacted tomato use in modern American gardens. Livingston pioneered modern breeding of tomatoes in the late 1800s and early 1900s, selecting varieties that were more uniform in shape and had a greater diversity of color – red, pink, and yellow. Following the work of Livingston, the diversity of tomatoes available in seed catalogs exploded. This diversity continues to grow even today with professional and amateur breeders tinkering with crossing varieties to create new and unique tomatoes for garden and farm use. In fact, it is partly because of the work of many amateur and backyard breeders that tomatoes are one of the few crops seeing an increase in cultivated diversity. Unlike tomatoes, most food crops are increasingly selected for a narrow set of commercial traits, leading to a decline in genetic diversity.
Let’s talk about traits
The shear diversity within tomatoes is astounding, and can be overwhelming. Characterizing the diversity can be helpful when narrowing down your tomato search. Let’s look at several different tomato traits representing this tomato diversity.
The tomato seeds you purchase will often be referenced according to their breeding type, which describe the way the varieties are developed during the breeding process. Let’s take a look at the basics to help clarify these terms.
- Open Pollinated (OP) – With these varieties, pollination occurs by natural means such as wind, birds, and bees. It may also include self pollination. This type of tomato has stable genetics; if you grow an open pollinated variety and save seed from it, the resulting tomato seed will be the same as the tomato you saved seeds from.
- Heirloom – This is a type of variety, which is often, but not always, open pollinated, was developed prior to 1950 when hybrids started to become more prevalent. Heirloom tomatoes have been passed from generation to generation, with a history that is likewise passed along in this exchange. Some heirlooms that were developed by seed companies prior to the 1950s continue to be favorites of gardeners and farmers today!
- Hybrid (F1) – A variety that is created by crossing two parent lines that are ‘pure lines’ (they produce sexual offspring that closely resemble the parent plants) to create an F1 (first filial generation) hybrid of the two parents. All dominate traits are expressed in that hybrid, which results in what is known as hybrid vigor. As a result of hybrid vigor, F1 (hybrid) plants are more vigorous, disease resistant, and high performing than their parent lines and other ‘OP’ varieties. Unfortunately, you cannot save seeds from hybrid varieties and expect the same results next year. If you save seed from a hybrid variety, you won’t get plants that are genetically the same. They will be a recombination of all the traits of the two beginning parents, resulting in a diversity of traits. The burst in production resulting from hybrid vigor will also be lost in this next generation.
Tomatoes can be further grouped into their different growing habit types. Knowing the different types helps you find the type of tomato that best fits your garden or farm space, and management practices.
- Indeterminate – Plants continue to make new growth and flower until killed by frost, disease, or human or animal intervention. They take up the most space and are the most common type of tomato plant. This type is typically pruned methodically to focus energy into fruit production and reduce disease potential.
- Determinate – Plants have a genetic trait that signals to the plant to end vertical growth and flower production. This results in a short time span for ripe fruit harvest, which is attractive to commercial growers. This type is often not pruned heavily, which is also advantageous to commercial production.
- Semi-Determinate – This type is somewhere between indeterminate and determinate. While technically indeterminate, they often have a more concentrated fruit set and ripening period and have more compact vines. Pruning suckers is optional for this type.
- Dwarf – These plants are indeterminate, but much, much shorter. Think of them as tomato plants where a traditional tomato cages actually work! They top out at 3-5 feet tall and are perfect for planting in containers. Dwarf tomato varieties were relatively unknown until the work of the Dwarf Tomato Breeding Project, which has collectively bread over 120 new varieties of dwarf tomatoes in the past 15 years.
Tomatoes come in a wide array of shapes, types, and sizes! What you plan to do with your tomatoes will drive what type/shape you pick to grow. These are the most essential fruit types, but there are many more sub classifications and in-between types!
Cherry – Single-bite tomatoes that typically are very sweet and perfect for fresh eating off the vine and in salads.
Saladette – Two-bite tomatoes that are generally bursting with flavor, and are great for snacking, roasting, dehydrating, and in salads.
Paste/Roma – Oblong in shape, this tomato is characterized by firm, meaty interiors with less seeds and juice. This makes them perfect for making tomato sauce, salsa, and canning.
Slicer – Tomatoes that work well on a sandwich! These tomatoes make your BLT dreams come true – juicy, full flavor, and delicious!
Tomatoes come in a rainbow of colors (well, almost), but did you know that the outward color of a tomato is determined by the combination of flesh and skin colors? Tomato skin is partially translucent, which means the flesh color appears through the tint of the skin color to create some truly magnificent color combinations.
Red – This quintessential tomato color is courtesy of a pink flesh and yellow skin, which presents itself as red to the eye. Next time you slice open a red tomato, peel back some of the skin to see that, in fact, it is yellow!
Pink – This type of tomato has pink flesh and clear skin and appears pink from the outside. A great example of a pink tomato is ‘Brandywine’.
Yellow/Orange – These types of tomatoes can have a couple of different skin/flesh combinations, including yellow flesh with clear skin, yellow skin and yellow flesh, yellow skin and white flesh. A commonly known orange tomato is ‘Sun Gold’ that is a cherry tomato prized for its sweetness.
Purple/Brown – This color combination has only recently become more common. They are characterized by flesh that is a very deep crimson color with some green pigmentation typically around the seeds. Crimson flesh with clear skin appears as a purple tomato from the outside. Examples of purple tomatoes are ‘Cherokee Purple’ and ‘Black Cherry’. Crimson flesh with yellow skin looks brown from the outside. An example of this type of tomato is ‘Cherokee Chocolate’.
Green – This is a unique and challenging tomato to pick. Green tomatoes can have yellow skin and green flesh (they turn a bit more yellow when ripe) and clear skin with green flesh. Since they can be difficult to tell visually if they are ripe, the squeeze test is best to determine ripeness. Examples of green tomatoes are ‘Green Zebra’ and ‘Emerald Giant’.
Bi-colored – These tomatoes are unique in that their flesh is typically two different colors. A great example of a bi-colored tomato is the variety ‘Ruby Gold’.
Striped – This tomato breaks the mold of the skin/flesh paradigm. These unique types have skin that is multiple colors, often very striking. Great examples of striped tomatoes are ‘Green Zebra’, ‘Bronze Torch’, and ‘Red Torch’.
And Many, Many More – There are even more unique and diverse color combinations out there and tomato breeders continue to work to bring even more unique and dazzling colors to your garden or farm.
Even though we love the variety of shapes, sizes, and colors of tomatoes, when we really get down to it, the main reason we grow tomatoes is for their flavor! And, of course, describing tomato flavor can be tricky. Tomatoes are a balance between sweet and acidic. Research shows that most tomatoes generally have similar acidity (pH) levels, but the sugar content varies widely. A tomato that is perceived as sweeter has a higher sugar content, which masks the acidity. So, if a tomato seems overly acidic, it likely has lower overall sugar. Texture – is the flesh mushy or firm? – and skin thickness – is the skin delicate or tough? – are also important flavor influencers. Tomato flavor is all over the map, from sweet, to acidic, to dull, to balanced. There are endless flavors to find in all types of tomatoes. Whatever your preference, you’re bound to find something you like!
Tomato Diseases and Pests
It is no surprise that our dreams of growing the most perfect tasty tomato can be quickly derailed by pests and diseases. Whether it be diseases like Septoria leaf spot, early blight, late blight, or pests like tomato hornworms, tomato fruitworm, root knot nematodes, deer, or voles, most gardens and farms experience some pressure from these forces at some point during a growing season. Lucky for us, tomato breeders continue to develop varieties that tolerate or are resistant to certain diseases. If you are facing problems with certain diseases or pests, search for varieties that are bred to be resistant to your particular issue. For example, when growing tomatoes in my garden in Wisconsin, I face a lot of problems with Septoria leaf spot and blight. Over the years I’ve found a few varieties that tolerate these diseases more readily, including, Bronze Torch and Damsel tomatoes.
Finding the Best Tomato!
So, what makes the best tomato? That depends on you and the traits you’re looking for. Choosing a variety that is adapted to your environmental conditions, cultural practices, market, use, storage/handling, and, of course, flavor and color preferences, will help ensure tomato success. The beauty of growing tomatoes is that there is an endless diversity to explore and enjoy. Over time you’ll begin to understand what tomato traits are most important to you and you’ll hone in and find your favorites that are best for your growing conditions. Cheers to learning about, growing, and (most importantly) eating tomatoes!
If you’d like to dive even deeper into tomatoes, I recommend checking out the book Epic Tomatoes, by Craig LeHouiller. Craig is incredibly knowledgeable when it comes to tomatoes, and his enthusiasm for growing them is infectious.