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There are so many different ways to construct a trellis for your tomato plants, and each way has it’s own advantages depending on your garden layout. After having so much success with this A-frame string trellis, I am definitely a huge fan! I still use cages for my determinate tomato varieties, but for my tall-growing indeterminates, this method works great. You can also use a string trellis for determinate tomatoes if you don’t prefer the cages, but in that case you wouldn’t need to make the structure as tall. Everything you need to know about how to build this trellis and more is outlined in this post, so let’s get into it!
What is a string trellis?
As the name would suggest, this type of trellis uses string to train vining plants upward. As the plants grow taller, you continue to wrap the main branch around the string to keep the plant from falling over. There are many different variations of a string trellis and different structures can be utilized to fit your needs. All you need to construct this type of trellis is some type of thick string, and something high above the plant to tie it to. Building an A-frame is the easiest way to accomplish this in my garden and I love that it’s something I only have to set up once and can continue to use year after year.
Indeterminate vs. Determinate Tomatoes:
Indeterminate tomatoes: Continue to grow and produce fruit throughout the entire growing season, reaching anywhere from 6-12 feet in height. These tomatoes require tall trellises for support.
Determinate tomatoes: Reach a determinate height, usually around feet, and produce all their fruit at once. Tomato cages are typically sufficient support for these types of tomatoes.
*Always make sure you know what type of tomatoes you’re growing so you are prepared with the right type of support! You should be able to find this info on the seed packet or just by doing a little research on the variety you plan on planting.
Benefits of using a string trellis for tomato plants:
- Supports vertical growth for a variety of vining plants (not just tomatoes)
- Maximizes space and production
- One trellis can support many plants
- More ties can easily be added for extra support
- Cost is significantly cheaper than buying cages
- Easy access to tomatoes when harvesting
Supplies you will need:
- 5 sturdy wood posts (7-12 ft long): I just used 1-in x 2-in x 8-ft Whitewood Furring Strips from Lowe’s. Somewhat random but they work perfectly and they conveniently come in a pack of 5.
- Twine (or any thick string): Just make sure it’s thick and strong enough to support a mature tomato plant, which can be quite heavy when covered in tomatoes.
Optional:
- Tomato clips: Another option for keeping the plant attached to the string so you don’t have to keep wrapping the stems.
- Landscape staples: Another method for securing the string to the ground instead of burying the string under the roots. (These are a good option if you’ve already planted the tomatoes before
Step-by-step guide to building an A-frame string trellis:
Step 1: Measure
Start by marking the spots where the posts will be going into the ground. This will vary depending on the size of your garden bed, how many tomatoes you’re planting, etc.
Note: When measuring height, keep in mind that several inches of the posts will be underground.
Step 2: Stake the posts into the ground
You may need to use a shovel to dig a small hole to bury each post by about a foot. This will ensure the structure doesn’t sway or lean.
Step 3: Tie stakes together to make an A-frame
About a foot down from the top, tie the posts together using twine. Make sure they are tightly secured.
Step 4: Fit top post into position and tie it down
Rest the final post horizontally atop both a frames (pictured left) and use twine to fasten the post so that it won’t shift.
Step 5: Attach string
Determine exactly where your tomato plants will be planted into the ground and attach a line of string directly above each spot. Double-tie the string to the post, then pull it taut to reach the ground, then give an extra foot of slack before cutting the string.
Step 6: Plant your tomato plants
Dig the hole for your tomato plant, then tie a knot at the end of the string and lay it in the hole. Place the plant on top, then fill in the dirt so that the string is buried under the roots. Make sure to leave a bit of slack in the string so that you can continue to wrap it around the stem as it grows.
Pro tip: As the roots develop the string will become embedded and stay secured underground. Tying a knot at the end is a way to ensure it stays anchored.
Important tips for success:
- Make sure you use sturdy posts to carry the weight of all the plants. (I learned this the hard way!)
- Don’t plant more than 6 tomato plants per trellis if you’re following my exact method, although more plants can easily be supported by using stronger posts.
- Tie extra strings to train up side branches or prune suckers to avoid too much weight on one string.
- Do not tie the string around the base of the plant, as the string will suffocate the stem as it becomes much thicker.
Other plants that can be grown up a string trellis:
- Cucumbers
- Beans
- Peas
- Luffa
- Other vining vegetable plants with light weight fruits
As you can see, this A-frame string trellis is such a quick and easy method and there are endless ways to adjust it so that it’s suitable for your garden. Gardening is not supposed to be too complicated and playing around with different types of support and learning by trial and error is all part of the fun! Perhaps there are other methods that will work better for you, or maybe this is just what you’re looking for. You’ll never know until you give it a try! If you do use this trellis method, let me know about your experience in the comments down below. I’d love to hear your feedback!
