Last week I promised you all an official update on how the caterpillar tunnel experiment went. I know a few of you were heartbroken to learn that this was not in fact a fun tunnel that we let caterpillars run through all day, but instead it was an effort to save our sad looking tomatoes.

At the beginning of the season, before we put the caterpillar tunnel up, the field tomatoes looked very stressed. They had gotten their leaves pelted by so much rain and the soil was soaked. As we hustled to get the tunnel up before yet another 2″ rain, we worried that it might be too late for them to recover. I am happy to report that the exact opposite happened. We put the caterpillar tunnel over the tomatoes, and in just a few weeks, they looked like entirely different plants. The leaves went from a dry, shriveled, brown color to a soft, vibrant green color. The plants started producing more leaf sets, growing taller, and eventually putting on flowers and fruit. We think the protection from the elements really saved them because the rest of the field tomatoes developed early blight.

The fruit has been slow to ripen, but that could be because we pinched off the first one or two sets of flowers in an effort to convince the plant to focus on getting healthy rather than producing fruit. We have been able to harvest a few tomatoes, but most of the fruit on the plants is still green.

The most important factor in determining if this tunnel was a success came down to the taste. First, for background, we haven’t been satisfied with our greenhouse tomatoes for a few years so this year we tested out new fertility sources. Previously, our nitrogen source was coming from fish fertilizer, and our potassium source was mineral based. Nitrogen is important for the chlorophyll formation in plants. Chlorophyll is what makes plants green which allows them to absorb sunlight through photosynthesis. Without adequate nitrogen, plants won’t be “green” enough to absorb sunlight thus stunting their growth, and possibly preventing them from fully maturing. Potassium is important for plants because it aids in regulating the rate of photosynthesis, and it is associated with the movement of water and nutrients throughout the plant. Without adequate potassium, plants have reduced yield, stunted growth, and poor flavor. 

Our previous fertilizer mixture worked okay (though applying fish fertilizer through drip tape is a smelly hassle), but we wanted to see if we could do better so we tried an amino acid based nitrogen. This is beneficial to the plants because amino acids are immediately available for the plants to absorb. The fish fertilizer delivered nitrogen in the form of proteins which can take a while to break down so they can be absorbed by the plants. We also switched to using a plant based potassium source instead of a mineral based source. Mineral based sources can often lead to a build up of minerals at the roots of the plant, preventing the plant from being able to absorb other nutrients. We also added calcium and micronutrients to round out the program.  

Farmer Janaki thought this new fertilizer combination made the greenhouse tomatoes taste significantly better than in previous years. This meant the caterpillar tunnel tomatoes had to be really great in order to earn the top spot for best tomatoes on the farm this year. We had lots of people taste testing, and we all came to the same conclusion: for our Geronimo (large slicing tomatoes) we compared one from our regular greenhouse and one from our caterpillar tunnel, and the greenhouse won. They both had a similar texture, but the greenhouse tomato had more flavor. We also compared an Early Cascade (small canning tomato) from outside and one from the caterpillar tunnel. In this test the caterpillar tunnel won. Again, they had similar textures, but the appearance and flavor of the caterpillar tunnel tomatoes was better. Oddly, the caterpillar tunnel fruit ripened later than both the high tunnel and field tomatoes. We only did a small sample so far, and this is just one year, so we are excited to keep this in mind and see if we feel the same again next year. In farming, there are so many variables that it’s hard to run true experiments that inform results year-to-year, but we keep trying to zero in on better ways of growing healthy food!

In your share this week:

Marcella Hazan’s Tomato Sauce 

Marinated Vegetable Antipasto

Vegetable suggestions: Blanched and chilled broccoli, cauliflower, and carrots.  Onion, celery, sweet peppers, zucchini

Prepare appx 8 cups vegetables by cutting into bite-size pieces.  Bring marinade ingredients to a boil in a larger saucepan.  Add approximately 2 quarts of cut up vegetables – cover and cook 3 to 4 minutes, stirring once.   Uncover, cool and refrigerate for at least two hours. Drain before serving.