The Vegetable Garden

Prune and Trelis Your Tomato Plants

  • Written by Kathy Anderson

For many home gardeners, the tomato crop is often a source of pride. Gardeners often compete to see who can grow the earliest ripe fruit, the biggest or most flavorful tomato. The desire for perfect tomatoes sends many gardeners to their local garden centers in search of the latest potions or products that promise to help them achieve their goals.


A simple way to ensure a larger number of picture-perfect tomatoes is to keep the fruit and foliage up off the ground. Tomato plants are susceptible to fungal diseases that are transmitted when infected soil splashes up onto the foliage during a rainfall. The fruit is more susceptible to slug and insect damage or rot if it is allowed to rest on or near the ground. This problem can be easily remedied by trellising your tomato plants to keep them up off the ground.

You can either purchase a ready-made tomato trellis or cage, or you can make your own. Ready made tomato cages can be purchased at garden centers, from gardening catalogs and sometimes at hardware stores. Styles vary, but the most common tomato cages are made of heavy wire and are either round, square or triangular. I have found that the round cages are often too small to support a mature tomato plant that is loaded with heavy fruit. I prefer the square or triangular cages because they can be folded flat for storage over winter, they tend to be roomy enough for large plants, and two cages can be linked together to support one very large plant or two plants together.

You can easily make your own tomato cages with materials found at any hardware store. Woven or welded wire fencing makes great tomato cages. Choose fencing that has gaps between the wires large enough to reach through to pick your tomatoes. Use a wire cutter to cut the fencing to a length of about six feet, bend it into a tube shape and use a pliers to bend the horizontal wires on one end around the vertical wires on the other end so the cage holds its shape.

Square or triangular cages can also be built with lumber. Start with four upright pieces, roughly three feet high. Nail crosspieces on the outside of the upright boards on all sides, one set all around the top and attach another set about 18 inches below the top boards to make a 4-sided enclosure with two rungs on each side.

If you’re growing a large number of tomato plants in rows, you may wish to create a large-scale trellising system, much like what is used to support berry canes. You’ll need some heavy gauge wire and metal fence posts, often referred to as T-posts. These can be purchased from farm supply stores. At both ends of the row of plants, sink two posts into the ground, placing the posts about two feet apart, one on either side of your plants. Then attach the wire at two or three levels between the posts. As your tomato plants grow, they will be supported by the wires. If you have a particularly long row of tomato plants, you will want to add more posts along the length of the row so the wire doesn’t sag under the weight of the heavy plants.