If you plant climbing crops like peas, cucumbers, and tomatoes in your garden, then you will want to give them support as they climb. Not only is a trellis a great way to support climbing plants, but it can also save space and make your garden look nice. The height of your trellis will depend on the height of your plants at maturity.
So, how tall should a trellis be? A trellis that is 6 feet tall will allow adequate climbing height for most plants, while still allowing you to harvest most of the crop easily. If you want to provide more than 6 feet of growing height for plants, you may want to use a lean-to, A-frame, or arch trellis for support.
Let’s take a look at some of the types of trellises you can use to support your plants. Then, we’ll look at how tall some common plants can grow, just to give you an idea of what to expect and what you will need for a trellis.
How Tall Should A Trellis Be?
A 6 foot tall trellis will be high enough to support most plants. Anything that grows taller than 6 feet can curl over and hang down as it continues growing.
A trellis only needs to be as tall as the plants that will be climbing up the trellis. If you make the trellis too tall, then it will be difficult for you to harvest anything higher than 6 feet up.
You can always use a ladder for harvesting, but I wouldn’t risk a broken arm or leg for a few pea pods. It’s a much better idea to choose your type of trellis wisely.
Types Of Trellises You Can Use
There are lots of options for a garden trellis, depending on your situation. If you have limited space in your garden, you might want to start with the first one: a wall trellis.
Wall Trellis (Flat Trellis)
A wall trellis, or flat trellis, is just what it sounds like. It stands up perfectly straight, just like a wall, allowing plants to grow straight up.
A wall trellis can be made of bamboo, wood, twine, rope, plastic, or metal. For more information on the types of twine and their uses, check out my article on twine.
You can buy a trellis or make your own, but be sure that it is sturdy enough to stand up to wind and the weight of plants growing on it.
You should probably limit the height of a wall trellis to 6 feet or so, since it will be difficult to harvest anything above 6 feet up without a ladder. Remember that part of the trellis will be buried to provide support, so a 6 foot tall trellis might have a total height of 7 feet (1 foot underground and 6 feet above ground).
A wall trellis is a good choice if you have limited space in your garden, since it encourages vine plants to grow upwards instead of outwards (as cucumbers and other plants tend to do without support).
One drawback of a wall trellis is that you will need to tie some plants to the trellis as they grow. For example, tomatoes do not have tendrils to help them climb, so you will need to use twine to tie tomato plants to the trellis at intervals as they grow.
Cucumbers, on the other hand, have tendrils to help them grasp things as they climb. They should have no problem holding on to a vertical trellis as they grow.
A lean-to trellis is a good option if you choose tall plant varieties (for example, some pea plants can grow to a height of 8 feet).
A lean-to trellis allows you to give plants more growing height while also making it easy to harvest your produce. The idea all comes back to mathematics and triangles – specifically, right triangles and 3-4-5.
If you make a right triangle with a base 4 feet long and a height of 3 feet, then the diagonal will be 5 feet long. If you double the dimensions, a base 8 feet long and a height of 6 feet will give you a diagonal of 10 feet.
The idea is to let your plants grow up along the diagonal, rather than up the vertical side of the triangle. This has two main advantages.
First, your plants have more space to grow, and it is still manageable to harvest them without a ladder. Also, you don’t need to tie tomatoes or other plants, since they can grow up the diagonal without falling over.
In addition, the lean-to trellis provides space underneath where you can plant shorter crops, such as lettuce or onions.
The only thing you want to remember is to make the width of the lean-to trellis reasonable, so that you don’t have to reach or bend over too far to harvest from your plants.
I would recommend taking a board 5 feet long by 3 feet wide, and supporting it at one end with a couple of boards that are 3 feet high. You may want to use slightly taller supports (perhaps 4 feet) and drive them one foot into the ground, so the lean-to is more stable in the wind.
An A-frame trellis takes the concept of a lean-to trellis one step further. Instead of having one diagonal for plants to grow along, an A-frame provides two diagonals for plants to grow along.
An A-frame trellis is equivalent to taking two lean-to trellises and putting them together, end to end. With an A-frame, you can grow two rows of plants, one growing up each side of the A-frame.
For very tall plants, you can plant on only one side of the A-frame, and let the plants grow up one diagonal and then down the other diagonal as they cross the peak of the A-frame.
As with a lean-to trellis, there is plenty of space underneath an A-frame trellis for planting shorter crops. You might want to make sure to plant shade-loving crops, especially as the season goes on and the plants growing on the trellis block out more light underneath.
An arch trellis is almost the same idea as an A-frame trellis, but it has a curved top instead of a pointed top. You can let plants grow up both sides of an arch trellis and meet at the top.
For tall plants, you can also plant on only one side of the arch and let the plant grow to the top from one side and then back down the other side.
An arch trellis is great if you want a more decorative support system for your plants. You can also make arches tall enough that you can walk underneath them as you move up and down your rows of plants.
One drawback of the arch trellis: if the arch is too wide or too tall, you may have difficulty harvesting anything growing higher up on the arch.
A teepee trellis allows plants to climb up and around the teepee at the same time. This allows plants the space they need to grow, without making it difficult to harvest at the end of the season.
A teepee trellis is another good space-saving option for your garden if you don’t have a lot of real estate to fill up.
How Tall Do Vine Plants Grow?
Remember that tomatoes, cucumbers, and other plants can come in vine or bush varieties. Vine varieties will grow tall and climb well.
On the other hand, bush varieties are difficult to support with trellises or other methods, and they are best left to their own devices, taking up whatever space they want.
If you have lots of space in your garden, go with bush varieties. Otherwise, choose vine varieties, especially if you want to put your trellis to good use.
Remember that different plants have different heights at maturity. Even different varieties of the same plant can vary quite a bit in their maximum height. Some of the heights for various plants:
- Peas – some shorter varieties of peas can max out at 18 to 24 inches (such as Patio Pride), while others can grow over 5 feet tall (such as Super Sugar Snap). You may be able to find and grow varieties of pea plants that grow to 8 feet tall or more! It is probably a good idea to use a lean-to, A-frame, or arch trellis for growing peas.
- Cucumbers – some shorter varieties of cucumbers may only grow to 1 foot tall (such as the Saladmore Bush Hybrid), while others can grow to 6 or 7 feet tall (such as the Baby variety). An ordinary wall trellis is probably sufficient for most cucumber varieties.
- Tomatoes – Some determinate varieties of tomatoes, such as dwarf varieties, may only grow to 1 or 2 feet tall. However, indeterminate tomatoes can easily achieve a height of 6 feet or more, and 12 foot tall tomato plants are possible. For determinate tomatoes, a wall frame is fine, but you will need to tie the tomatoes. For indeterminate tomatoes, you will probably want to use a lean-to, A-frame, or arch trellis. Remember that you will still need to tie tomatoes to an arch trellis.
- Squash – Most squash plants will achieve a maximum height of 2 to 3 feet, so they can be safely supported with a wall trellis that is 4 or 5 feet tall. It will be no problem to harvest at the end of the season!
If you want to check out any of the plant varieties mentioned above, go to parkseeds.com to learn more about the plants.
By now, you should have a better idea of how tall your trellis needs to be to support your plants. You also have some ideas for what type of trellis you can use in your garden.
I hope you found this article helpful – if so, please share it with someone else who can use the information. If you have any questions or advice of your own about trellises, please leave a comment below.