You say Tomato, I say Solanum lycopersicum

The vegetable that is a fruit

Some of you know that the tomato is technically a fruit—which means that it is a seed-bearing structure in flowering plants formed from the ovary after flowering. But the tomato defies this definition because what we generally consider as a fruit is usually sweet. The tomato can impart a sweetness of sorts, but it has so much more versatility as an ingredient than fruits usually possess. Of course, it also has more versatility than most vegetables too.

I promise you, we’ll get to the part where we discuss how to grow a tomato. But you should know some of this fruit’s history, because history is important and interesting, too.

SOME HISTORY

It’s hard for many of us to imagine Italian food without tomatoes, but the fact is, the tomato wasn’t even introduced to Europe until after 1521, when Hernán Cortés, a Spanish raider, pillaged the Aztec city of Tenochtitlán (now called Mexico City), bringing back, amongst his stolen wares, the tomato. It was planted in gardens but not eaten very much until the 1600s, many Europeans thinking the plant poisonous. And even then, only rarely did anyone eat them—some doctors even said they caused harm to the body and mind. The Nahuatl (the language used by the Aztecs) word tomatl gave rise to the Spanish word tomate, from which the English word tomato derived.

The tomato was domesticated much earlier in Mexico, probably at around 500 BC, and by the time Europeans arrived in the Americas, there was already an incredible variety of selections. A Franciscan friar and missionary Bernardino de Sahagún recorded in the 1500s that he saw a great variety of tomatoes in the Aztec market at Tenochtitlán: “. . . large tomatoes, small tomatoes, leaf tomatoes, sweet tomatoes, large serpent tomatoes, nipple-shaped tomatoes, and tomatoes of all colors from the brightest red to the deepest yellow.”

He also described Aztecs cooking as an astounding variety of sauces and dishes being sold in city markets. So, long before the Spanish scrounged up the fruit and took it back to Europe and scratched their heads for a few centuries, it was being employed in numerous ways by the indigenous people of the Americas, probably using some methods that are now lost with time (and genocide). When you steal something and don’t respect the culture from which you stole a thing from, its value is often lost.

And as far as Italian food, it wasn’t until the 19th century that the Italians would develop the tomato as the important ingredient it is today. Oddly enough, that development coincided and helped fuel Italy’s attempt to distinguish itself as a people from France, Spain, England, and the rest of Europe. So strange that these colonialist nations, who pillaged the world around them, would use some of the things they took from the Aztecs as part of a nationalist attempt at distinguishing themselves. Even the Italian national flag, incorporated red as part of a tricolor design, which helped reinforce the tomato as a major staple in the Italian diet. Indeed, a great many Italian dishes developed around this time deliberately incorporated red, white, and green colors as a way of reinforcing national pride. Weirdos.

The tomato deserves to be thought of as what it really is, a development of the Aztecs. And we could really learn a lot about the potential of this beautiful fruit by looking at how it is used in the various cuisines of tropical America, particularly cuisines that attempt to shrug off the impositions of colonialism and uphold indigenous knowledge.

That isn’t to say you need to feel guilty eating bolognese or spaghetti. Italian food is magical. And they have harnessed the flavor of this fruit rather well. It’s just nice to remember that this fruit has a longer history, and that maybe the Europeans have more to learn about this nightshade.

GROWING TOMATOES

The tomato is technically a tropical plant; a sprawling, vining perennial that rambles over other plants competing for light. The fruits probably evolved originally as a bird-dispersed plant like many other nightshades. The original fruits were small and bumpy.

The modern tomato is usually a lot more smooth-skinned (though a few heirloom varieties are bumpy or ribbed) but still most often displays the rambling growing habits. They are thus, trained up in “tomato cages” or tied up with string, fencing, or other structures to control and direct their growth.

The tomato, for us in Baja Arizona, is a warm-season crop. In some parts of our region, where frost is more of a rumor than a reality, or in greenhouses, tomato plants can live for several years, though they don’t always look great or produce as well when they have been growing for a long time.

We generally plant them in spring, either after threat of frost, or sooner (protecting young plants from any frosty nights). And unlike many types of other plants, when you plant a tomato, you can bury the base of the plant, the stem, snipping off lower leaves, where the plant will set out more roots. When we give this advice we always mention that this is definitely NOT a practice you should try on a lot of other plants, as it is one of the reasons people fail when they plant other species of plants.

Tomatoes can grow in full to part sun. Plants that are in full sun may look more haggard in the foliage when the summer really kicks in, but they will produce more fruits. Plants in too much shade will not fruit as much, and they will be more susceptible to pest problems.

When the summer heat starts slipping into the triple digits °F, and the evenings not getting below 80°F, they can stop producing fruits all-together. Starting your plants early (as early as January or even December if you have a plan for frost protection) will help you get a head start and get lots of fruits before that heat hits. By the time summer comes, you can pull up those plants. Some people plant a second flush of tomatoes during the monsoon for a fall harvest which will last until plants are frozen.

With the right selections, lots of the right soil amendments and organic plant food, and layers of mulch around the plants in sunken beds, you can even sometimes still coax fruits from plants growing in summer. They may not be quite as red when the temperature is above 95°F; tomatoes have a hard time producing red pigment in hot temperatures.

Tomatoes like regular, even moisture, and since they are fruiting plants, you should prepare the soil with phosphorus rich ingredients (look for the middle number on your organic fertilizers). If you get a lot of malformed fruits, this is something called blossom end rot and it is usually caused by a combination of factors—uneven watering also can contribute to this problem. Often problems with blossom end rot is a sign that the balance of nitrogen and phosphorus in the soil is not favoring phosphorus and our alkaline soils can exacerbate this.

In general, prepare the soil with well-made compost, and some organic fertilizer that has a higher middle number. During the season you can feed with fish emulsion, and you can use epsom salts for magnesium (tomatoes seem to use a good amount of this secondary nutrient). You can also feed with any blended organic fertilizer meant for fruiting plants.

Many tomato cages sold on the market still flump over when tomatoes really start growing and have lots of fruits. At our house, we’ve begun using the method of tying plants upward (we have a wooden frame above our garden beds that we can attach the strings to). Also, there are some sturdy rectangle shaped tomato cages that are wonderful, albeit expensive.

We have grown our plants in full sun all summer and have had wonderful crops. But we have begun using about 30% shade cloth over the garden just to take the edge off the heat and they seem to really like that.

We never really fight any pest problems in our garden—you will get the occasional aphids (more likely on plants in too much shade) or the tomato horn worm which is the larvae of the beautiful five-spotted hawkmoth (Manduca quinquemaculata). The giant caterpillars really freak some people out. On young plants this guy can destroy the whole plant, but on a more mature plant, the caterpillar will eat some of the leaves, and the stems will reproduce new foliage after the feeding. If you don’t want to host this caterpillar, consider putting it on another one of its food plants—they can use almost any plant in the nightshade family, and in many yards there always seems to be a volunteer nightshade like wild tobacco (Nicotiana trigonophyllum), tree tobacco (Nicotiana glauca), silverleaf nightshade (Solanum eleagnifolium), or jimson weed (Datura spp).

TOMATO VARIETIES

We don’t have the space to consider all the varieties of tomatoes that are out there. There are almost endless variations in size, pulp texture, seediness, color, and shape. And you can try them all.

You are going to hear that you cannot grow the larger varieties like Beefsteak in Arizona. Let’s just start off by saying that this is simply not true. You can grow almost any variety of tomato, but you will have to consider the time it takes before it starts to fruit—like with any other crop—and time your planting accordingly. If you really want a Beefsteak, remember that most selections of this kind need 60-90 days from seed to fruit. Plant the crops that take longer to develop as early as you can (this is why many people will plant these crops before the standard last frost date). Remember that a frost can occur even after the average frost date (February 16) so even if you don’t plant “early” have a plan to protect young warm-season crops.

Some people will tell you to grow the crops you will actually EAT and USE. This is sound advice. And I generally follow it. But sometimes you just wanna grow something because it’s weird. And while that is not always efficient concerning space in the garden, it’s fun. In the past I have grown something I am unfamiliar with just out of curiosity only for it to become a staple as I become acquainted with the crop and start using it. Let the garden teach you. Have fun. Also, maybe try to grow the kinds of tomatoes you can’t find in the grocery store—especially since the crops often available in the grocery store are often selected not for flavor but shelf-life.

Do your homework: find out what the people who selected a said variety or heirloom were aiming for. Some tomatoes are meant for slicing. Some make great sun-dried tomatoes. Some were bred just to make tomato sauce. Know what you are likely to want, or try, and choose accordingly. Or, as suggested above, just try something for the heck of it.

I owe a personal debt to the tomato. As a young college kid, I was already fairly good at growing many other rare and weird plants—one day I decided I should try my hand at growing a tomato. Why not? It was my first real edible crop. I didn’t grow up in a home that cherished food, and I hadn’t yet developed any love for the kitchen. When I tried my hand at tomatoes, I was very successful. But suddenly I had so many fruits and I felt angst about wasting what I worked hard at growing. So the tomato drove me into the kitchen. I learned how to make sauces, how to sun-dry them, and even began to play with fermentation all because of this crop. It was my introduction to the kitchen and almost three decades later, I am a food fanatic. Thank you, Solanum lycopersicum.