How to Trellis Tomatoes for Maximum Yield
Keep your homegrown tomato plants off the ground to encourage a bountiful harvest.Posted Jul 19, 2016
“There ain’t nothing better in life than true love and a homegrown tomato,” goes the old saying, asserting that tomatoes produced in well-tended, backyard soil are equivalent to finding a soul mate. Fiery red and packed with swoon-worthy flavors, homegrown tomatoes dazzle salads or form meals in their own right (stuffed tomatoes anyone?). But like most garden crops (and most relationships), tomatoes require careful maintenance. For those of us growing indeterminate or vining-type tomatoes, they also require a little infrastructure.
Vining versus Bush Tomatoes
The first thing to consider when planning your tomato infrastructure is whether you are growing vine (indeterminate) or bush (determinate) tomatoes. Bush tomatoes grow for a shorter season, setting and ripening their fruit during a concentrated period. This makes bush varieties excellent for canning. It also means their height is limited and elaborate trellises are not necessary. For determinate tomatoes, a simple tomato cage or patio container will do.
In contrast, vining or indeterminate varieties will grow and set fruit throughout the season. These tomatoes need consistent pruning and commonly reach heights of six to ten feet or even more. Since most heirloom tomatoes are indeterminate varieties, you may find yourself growing a mix of bush and vine tomatoes to meet your needs. This will provide you with fresh tomatoes for slicing and dicing throughout the season, as well as a concentrated harvest for preservation.
For those who do grow indeterminate varieties, tomato trellises are an important addition to the garden. Not only do trellises keep vining plants off the ground, protecting them from a variety of pests, diseases and foot traffic, they also ensure plants receive adequate circulation and sunlight—two necessities to help reduce disease and hasten ripening. Trellising your tomato vines also enables you to grow a higher density tomato crop, helping you conserve valuable garden space for other crops.
Depending on the materials at hand and your pruning methods, the following trellis options provide the inexpensive and practical support your tomato plants need throughout the growing season.
Perhaps the simplest way to vertically support a vine is to tie it to a frame or other support using pieces of string or twine. String trellising is an inexpensive and readily available system that requires few materials. If you are growing your tomatoes in a greenhouse, you can eliminate the frame by attaching vertical strings to greenhouse studs or rafters. If your tomatoes are outdoors, practical options include:
1. Horizontal String Trellis: Best for determinate varieties (because this system makes pruning difficult), this method sees string running horizontally across a frame, forming a string support on either side of each plant. Construct a frame around your tomato row by driving wood or metal stakes at either end of your row and every 3-4 feet within the row. (Stakes can be approximately four feet, depending on your tomato variety). When the tomatoes are a foot high, tie string to an outside stake and begin weaving string horizontally across the frame, looping around each stake in the row. When you get to the end, weave back again on the other side of the plants. Each time your plants grow a foot, it’s time to weave a new row of string.
2. Vertical Hanging Trellis: Using wood or metal posts averaging 6-8 feet high, drive in supports on each end of your row and every 10-15 feet within the row. Connect the posts across the top with a single strand of high quality wire. Next, attach one string immediately above each tomato plant, letting it descend all the way to the ground. Wrap or clip each tomato plant to the string, winding or clipping as the plant grows.
Stake and String Combination
Another option for trellising tomatoes is the stake-and-string method. Similar to the vertical hanging trellis above, this method involves pounding a wooden stake next to each plant when your tomatoes first go into the garden. The stake provides early support for the tomato, which is later wrapped or clipped to a string suspended from the greenhouse ceiling or horizontal frame.
Cedar is a good wood to use for stakes since it is relatively rot resistant; your cedar stakes should last several years or more. Metal fencing stakes can also be used as an alternative. With wooden stakes, use a hatchet to taper one end of each stake to a point, and be sure to drive the stakes into the ground when the plants are young to avoid damaging any roots that spread laterally when the plants are more developed.
When choosing string for tying the plants to stakes, jute or sisal is ideal since this type of string is biodegradable. This is a big help when you’re clearing the plant skeletons after harvesting is complete. Instead of having to separate the strings from the plant stalks and branches, you can toss the whole works into a compost pile where it will all degrade together.
Hanging Fence or Netting
If you are a gardener who prefers to let your indeterminate tomatoes develop more than one “leader” or head, a single strand or stake will not provide enough lateral support for your developing plants. Instead, consider constructing a frame that will accommodate a length of fencing or netting as tall as your plants are likely to grow (6-8 feet is common). As the season progresses, clip, tie or weave your plants to the fencing. When tying your plants, form a loose loop around the stalk or branch so that as the plant grows and the stalk thickens, the string does not girdle (or choke) the plant.
After experimenting with different trellises for our indeterminate tomato crop, we have now adopted this relatively inexpensive system for all our vining tomatoes. We first saw concrete mesh in the garden at a friends’ house, who kindly pointed out that the material was both easy to come by and very affordable given its size and longevity. Manufactured from 9-gauge wire crafted into 6-inch squares, concrete mesh is intended to reinforce concrete in construction projects. The product rusts easily, but is firm enough to support itself and soft enough to cut without special tools. (Don’t worry about the rust, this type of fence material will last many years regardless of rust.)
Used in the greenhouse, concrete mesh provides a useful vertical support when attached with spacers to studs. (We keep it at least a foot from all walls to allow for adequate air circulation). Used outside, concrete mesh works well with a freestanding frame and is versatile enough for most pruning methods.
Wire Tomato Cages
These commercially available cylindrical galvanized wire tomato cages spike directly into the soil and are otherwise freestanding to a height of about 4’. Taller cages may be available in some garden centers, but we haven’t seen them yet in our locale. These cages are set over the young seedling and as the plant grows its branches will grow through the cage and be sufficiently supported. Smaller varieties of tomatoes do well in these cages, but taller varieties will need additional support as they outgrow the cage.
Tomato cages reduce the need for tying your plants to stakes, wire, string or a frame. You’ll still likely need to tie sagging branches to the cage in some place, as the fruit set can be heavy and unevenly distributed.
You can also make your own custom wire tomato cages by cutting lengths (about 5’ – 6’) of galvanized page wire, available at any store that sells wire for fencing. Use a heavy wire cutters to make the cuts. Page wire is available in 4’ and 6’ heights, and you can form each cut piece into a cylinder by bending the wire and fastening the cut ends over the leading edge of the wire. Now set the cage over your young plants. To keep the cage upright as the plant grows, you’ll need to drive a stake woven through the wire and into the soil on either side of the cage. The advantage of this method is you can size the cage to the type of tomatoes you plan to grow. And at the end of the growing season, these cages can be opened, stacked together and stored flat. This is very convenient.
Commercial tomato cages are usually tapered cylinders of wire, cone-shaped, with the narrow end closer to the ground; this arrangement supports the shorter branches of young plants. Your homemade cage will be a straight cylinder that may not be as convenient for tying the lower branches, but once the mid- and upper branches are supported the lower ones are usually lifted well enough off the ground. We’ve had good results with this type of cage.
With so many options available for supporting your tomato plants, it’s easy to conclude that tomatoes are more trouble than they’re worth. Yet finding the right method for your crop is as easy as considering your needs: when would you like to harvest your tomatoes? How many do you want to eat? Should you store any for the winter? And finally, how do you like to prune them? Answering these questions will help you sort through the options and choose what’s right for you. If only true love were that simple.
Shannon Cowan is an author, editor, and teacher who lives on six acres of land with her husband, daughters, and backyard chicken flock.