Above, tall and dark green okra plants and small bushy shishito pepper plants. Tomato plants can be seen in the background.
As part of the One Acre Farm CSA, you may have received some beautiful green/purple red tomatoes that look pretty much perfect. Or you received round red globe tomatoes that seem to shine like a bowling ball. These tomatoes were grown in the high tunnel and planted in the very early spring. It’s hard to compare the tomatoes grown in the field with these beauties!
Why do tomatoes thrive so much in the controlled environment of the high tunnel? There are many reasons. As we look at the results seen in these tomatoes, we are becoming increasingly convinced we should only grow tomatoes in the high tunnel!
Tomatoes do not like wet soil. Anecdotally we have heard stories about farmers who planted rows of tomatoes and because of one thing or another, essentially abandoned them for the season. When the tomato beds were remembered, the farmers went back to find beautiful and thriving tomatoes, even without consistent or regular watering! This makes sense because tomatoes originate from the Andes in western South America. Tomato ancestors were found in low rainfall/precipitation locations. Eventually these tomato ancestors were cultivated by humans to create the big, beautiful orbs we have today!
Tomatoes like air flow. If you look at a photo of tomatoes in the field and a photo of the tomatoes in the high tunnel, you might not even realize you’re looking at the same plant. The tomatoes in the field look like they’re growing wild, almost bursting from their trellising. In the high tunnel, the tomatoes are intensively pruned to look stark and naked. The plants only have enough leaves to keep the fruit shaded; any extraneous leaves are pruned off to allow the plants to breathe. It also prevents disease by enhancing air flow – just like mosquitos breed in stagnant water, disease breeds in stagnant air.
Tomatoes get most of their disease from the soil. Isn’t that surprising? Most disease that we find on the farm can be traced back to the soil. Not because anything is “wrong” with the soil, it just happens to be an enormous tub of fungus. Yum. If you’ve ever grown tomatoes, you might know the word “blight.” Blight is a term for disease from fungal spores that is carried by wind, water, insects, or little bunny rabbits. In the high tunnel, which has a lovely roof and walls, you have a lot more control about what can get to the plants. By pruning away all the leaves from the base of the plant, you reduce the likelihood of those leaves touching the soil and contracting a disease. We also line most of the high tunnel soil with landscape fabric to reduce the chances of any part of the plant (other than the root!) hitting the soil.
Tomatoes are like to climb. Tomatoes are indeed vines, and just like that pesky Virginia creeper vine that won’t leave your yard, vines sprawl and try their mightiest to get as much sunlight as they can. If not trellised, tomatoes will flail their spindly limbs in every direction, crawling over anything and everything. To mitigate having a mutant octopus/tomato in the field, we trellis the tomatoes, either from string hanging straight down from cross wire set up in the beam structure of the high tunnel, or by creating a sort of horizonal weaved basket “the Florida weave” in the field. The vertical method is unique because it creates wonderful air flow and makes it a lot easier for us to plant many plants close to one another (with heavy pruning, of course). The Florida weave method is fantastic because it’s a low input method of keeping the tomatoes contained, but it’s a lot of hard work to trellis all the tomato beds.
Four good reasons to grow tomatoes only indoors. Sounds pretty good, right? However, growing in a high tunnel does require many laborious hours of maintaining the high tunnel. One also must make sure that the soil does not get too worked. Just like bread that is kneaded too much, soil that is overworked will be lackluster in health and produce a subpar product. We need to be considerate and delicate with the limited resource of high tunnel soil. We’ll let it rest and replenish it with compost and amendments when necessary. These tomatoes just might be worth all the hard work!