Growing Tomatoes on Cinderblocks

I kept a couple of tomato plants in an unusual way this year. Instead of bracing them with the usual wire frames or wooden trellises I used cinderblocks. That’s right, I borrowed a few of those weathered gray cement blocks from other places in the yard (bought a few extras) and piled them loosely around the plants.

There was a reason for this. I wanted to see if they would work as a stone mulch while at the same time provide support for the notoriously recumbent plants. They weren’t the most beautiful of gardening props early in the season (later in the year they were completely covered), but the overall experience was such a success that I am certainly going to repeat the experiment this next year.

I started by shoveling a nice layer of homemade compost around the young transplants and then placed 4-inch thick cinderblocks – flat side down – around the plants and over the compost. This was basically a stone mulch except that the “stones” where extra thick and had a big opening between the bottom and the top. By placing them this way, I was hoping to retain ground moisture around the plants, but I didn’t want to restrict air movement. The blocks were perfect for this.

As the plants grew, I started placing other cinderblocks on top of the first ones. These I placed with the open side down in order to make the wall higher. This worked well for a few weeks but then the plants began growing more rapidly than expected. In order to keep the leaves off of the ground, I was forced to both raise the block layer (by adding more blocks) and add another wall of bricks adjacent to the first wall. As the season progressed, even this outer wall was completely over-grown.

The result of all of this exceeded my expectations. Because I didn’t use any artificial fertilizers (just my compost layer) the plants produced both an abundance of vegetative growth as well as a good fruit set. The two plants that I kept ended up covering about 100 square feet and reaching five feet high. I had a veritable thicket of tomato plants and yet almost none of the leaves were touching the ground. As a result, there was virtually no disease on any of the leaves the entire season. When I finally took out the plants (a week before the first frost in November) there were still hundreds of blossoms and developing fruit on the vines.

What surprised me most as I cleaned up the blocks was how dry it was around the base of the plants. This in spite of the fact that the area had received regular water (via the sprinklers) all season, and the canopy was lush and very full. It seems that the blocks had indeed kept the area well aerated even as they supported the plants. But they also kept the ground around the tomatoes from getting hot and the soil, just below the surface, was moist. Earthworms and other soil creatures were abundant.

I should also mention that the stems were thicker than I remember tomato stems to be. Normally when the branches are left to tumble to the ground, they tend to grow roots where they come in contact with the soil. My tomatoes were not allowed to do this. As a result, their stems were as thick as a silver dollar (thicker actually) like tomato plants that are grown in production greenhouses. I have no doubt that if there were to be no killing frosts, these tomatoes would have kept producing for months to come.