Advantages of Trellising • Main Types of Trellising Systems • Setting Up Your Tomato Trellis
by Andrew Mefferd, R&D, Johnny's Selected Seeds
The advantages of trellising make it a popular technique for use with many vining crops.
- Growing the vines on a trellis will keep them out of pathways.
- Trellising makes fruit easier to find, speeding and improving the ergonomics of harvest.
- Trellised vines can be grown at a higher density than vines that are sprawled, since they can make use of the vertical space over the plant, instead of growing into each other — which optimizes yield.
Trellising is especially important for tomatoes, where all these advantages apply and then some. Keeping the vines off the ground reduces exposure to soilborne pathogens, which will keep the foliage healthier. Airflow is better around trellised plants, which keeps the canopy drier and less vulnerable to fungal diseases.
For these reasons, most fresh-eating tomato crops are trellised.
There are a lot of different options for trellising tomatoes. The system that will work best for you depends mostly on:
- The type of tomato you are growing
- Where you are growing it
- How much labor you want to put into it
Most tomato trellising methods are variations on either the basketweave system or the stake-&-wire/hanging-string system. Each has its merits, and growers prefer to use them in lots of different ways.
Generally, basketweaving methods are best-suited to the bushier types of tomatoes — determinates and semideterminate varieties — and the hanging trellises most useful for the rangier, indeterminate varieties.
Below are the basics to help you choose and learn how to implement a system that will work well for your growing situation.
By late August, all that's visible of the basketweave are the top strings — the plants are upright, robust, and producing plenty of delicious ripe fruit!
Defiant PhR »
Indeterminate tomatoes can be basket-weaved as well, with one of two disadvantages. If they are pruned, this will be more difficult and time consuming. And if they are not pruned, fruit size will go down due to the sheer number of fruit set on an unpruned indeterminate plant. Also, unpruned, basket-weaved indeterminate plants will form a hedge of foliage which is susceptible to fungal diseases that can get started in the dense canopy. Unpruned, indeterminate basket-weave tomato production is mostly confined to arid areas because disease problems can be severe in humid areas.
Wand & Twine. When plants are about a foot tall, before they start to flop over, twine is tied to the end post, then looped around each stake down the row. At the end of the row, the twine is looped around the post at the opposite end, then looped around each stake on the way back so there is a string running along both sides of the plants to keep them upright. Additional strings are added higher up as the plants grow, every 8"–12", or before they flop out of the trellised area.
Our tomato twine is well suited to this job. The box it comes in has slits in the sides, so you can wear it on your belt and not have to hold it as you walk down the row.
This leaves your hands free to use another tool that makes basket-weaving easier — a wand made of a short length of PVC pipe or a stick with holes drilled in each end. The twine can be passed through the wand and tied to the first post, extending your reach so you don't have to bend over as you go. (See videos showing technique, listed below.)
Not only will the wand speed up your work, but your back will thank you at the end of the day.
View our Facebook Photo Gallery depicting this method »
The stake-&-wire/hanging-string system can be used both in the field and in protected-culture settings, and works well for pruned, indeterminate tomatoes.
This system makes it easy to prune and trellis indeterminate tomatoes because each stem gets a string, and any additional suckers are pruned off.
An indeterminate tomato plant with five or six fruiting clusters can exert 10–12 pounds of downward pull on its trellis, so pruning is essential, and the support system needs to be both tall and strong.
Stake-&-Wire / Hanging-String Set-Up
Stakes & Wire. To set up a hanging-string trellis, start with tall, strong posts, driven into the ground every 20 feet, with a line of strong wire, such as 12-gauge high-tensile wire, stretched tightly, between the posts.
If wooden or steel T-posts are used, a hole can be drilled at the top of each post through which the wire can be threaded and secured. If you are a welder, you may be able to burn the holes more quickly through metal T-posts. Steel U-posts come predrilled, eliminating this step.
Hanging Strings. A length of twine is tied to the wire at every point where a vine will be suspended, and then loosely tied at the base of the plant with an overhand knot. Hanging strings made of biodegradable sisal trellis twine facilitate clean-up at the end of the plants' lifecycle.
It is important not to make the knot at the base of the plant too tight, because it will cut into the plant as it grows. You can use a tomato trellis clip to attach the string instead of a knot. Tomato trellis clips are designed to bite onto the string securely, but to gently encircle the vinestalk.
As the vines grow, they can be attached to the string with additional trellis clips, or they can be twisted around the string to support the plants. Just make sure you always twist in the same direction, or you will unwind the string you have already twisted!
This method is more labor intensive, but works better for pruned indeterminates, than the basket-weave method.
Lower & Lean Tutorial »
Another variation on the hanging-string method in a greenhouse or hoophouse is to use Tomahooks or Rollerhooks to attach the overhead strings. These are strong, and conveniently allow the vines to be lowered and leaned, since they may outgrow their vertical space in a greenhouse. With this method, a spool is attached at the overhead wire, and when the plants run out of growing space, you can play out some of the string, about a foot at a time, and move the plants one position to the side so the vines don't pool up at the bottom and break. The plants at the ends of rows go around to the other side. This requires plants to be planted in double rows, two feet apart being a common spacing.
Hortonova Trellis Usage Comparison Chart »
View All Trellis Netting »
One variation on the hanging trellis system that can be set up either in the field or a protected culture setting uses trellis netting instead of hanging strings to support the vining crop.
Netting Trellis Set-Up
The first step of installation is just like the hanging-string method, where tall posts with holes at the top of them are pounded every 20'. With this method, as you are threading the heavy-gauge wire through the tops of the posts, you weave it through the mesh at the top of a piece of Hortonova.
As the plants grow up, they can be clipped to the Hortonova with trellis clips, or tucked into the square mesh, weaving them into the mesh.
We use this method on my farm for cherry tomatoes, because sometimes we like to let our cherry tomatoes develop more than two heads, and the mesh can accommodate any number of heads. This method also works well for crops like climbing beans or peas that don't have a discrete number of vines.
So whether you grow in the field, high tunnel, glasshouse, patio, backyard, hoophouse, or warehouse, give thought to what types of tomatoes you want to grow, consider the ergonomics involved and the resources you can apply, and choose the trellising option that best fits your needs. You will find you can customize the system to suit your preferences and the conditions at hand.
When your vining crops are provided appropriate trellising and support, your growing efforts will be more efficient and deliver optimal yields of premium fruit with fresher flavor.
- Lower & Lean tutorial, by Andrew Mefferd, Johnny's Selected Seeds Video »
- Basketweave tutorial, by Will Brownback, Spiral Path Farm, Perry County, Pennsylvania Video »
- Basketweave tutorial, by Mark Hutton, University of Maine Cooperative Extension Video »
- Basket-weave Trellising Tech Sheet PDF »
- 3 Ways to Choose Tomatoes: Growth Habit, Growing Environment, Fruit Characteristics Article »
- Johnny's Determinate Tomato Comparison Chart PDF »
- Johnny's Indeterminate Tomato Comparison Chart PDF »
- University of Georgia Commercial Tomato Production Handbook PDF »