Keeping a tomato plant growing vertically is an efficient way to use the space in your garden, decrease chances of airborne diseases and make maintenance and harvesting easier. You can make a simple trellis that will last for years of growing and have it installed in under an hour. Plan to make your trellis and install it before you plant your tomatoes for best success in not disturbing an existing root system.
Measure an area 16 feet long where you want to plant your tomatoes in a line. A 16-foot trellis should hold eight to 10 tomato plants. Lay a metal fence post at each end of your 16-foot space and one in the center, 8 feet from each end post.
Stand a post up one at a time and drive it into the ground 8 to 10 inches deep. Use a sledge hammer, if necessary, to drive the posts down. Wiggle each post to make sure it is secure and won't fall over in heavy wind.
Align your panel of fencing against the posts and even it up so it meets each post on opposite ends. Let the bottom of the panel rest on the ground but don't worry about burying it in the soil.
Secure the panel to the posts by using zip ties and pulling them tight to hold the panel up against the fence post. Use three evenly spaced zip ties on each post. Plant any tomato plants 2 to 3 inches from the base of the fence and train them on it as they grow taller.