Arch trellises are one of the most popular garden structures — but getting the width wrong is one of the most common mistakes.
If you’ve ever wondered how wide an arch trellis should be and how that affects its height, strength, and walkability, this guide will break it down clearly and simply.
Why Arch Trellis Width Matters
The width of an arch trellis directly determines:
- How tall the arch becomes
- How much space you have to walk through
- How well it supports heavy climbing plants
A common beginner mistake is assuming a wider trellis automatically means a taller one. In reality, wider arches usually peak lower, while narrower arches rise higher.
Understanding this relationship helps you avoid building an arch that feels cramped, unstable, or unusable.
What Determines the Height of an Arch Trellis?
Arch trellises are typically made by bending cattle panels or wire panels into a curved shape.
As a general rule:
- Narrower width → taller peak
- Wider width → shorter peak
This is because the panel has a fixed length. Spreading it wider lowers the curve, while bringing the sides closer together raises the center.
Ideal Arch Trellis Width (Most Gardens)
For most backyard gardens, a width between 5 and 7 feet works best.
Recommended widths:
- 5 ft wide – Taller arch, tighter walkway
- 6 ft wide – Balanced height and space
- 7 ft wide – Comfortable to walk through, slightly lower peak
Many gardeners choose 7 feet because it feels spacious and works well with raised beds on each side.
Arch Trellis Width vs Height Chart
Below is a general reference chart showing how width affects height when using standard cattle panels:
| Width (ft) | Side Wall Height (ft) | Peak Height (ft) |
|---|---|---|
| 2.0 | 6.43 | 7.43 |
| 3.0 | 5.64 | 7.14 |
| 4.0 | 4.86 | 6.86 |
| 5.0 | 4.07 | 6.57 |
| 6.0 | 3.29 | 6.29 |
| 7.0 | 2.50 | 6.00 |
| 8.0 | 1.72 | 5.72 |
This chart makes it easier to choose the right width based on how tall you want your arch to be.
Best Plants for Arch Trellises
Arch trellises work best with climbing or vining plants, especially those that benefit from airflow and hanging growth.
Popular choices include:
- Cucumbers
- Pole beans
- Squash
- Gourds
- Melons
Heavier crops benefit from wider arches with stronger support, while lighter vines can grow well on narrower, taller arches.
Final Thoughts
Choosing the right arch trellis width makes a huge difference in how your garden looks and functions.
For most gardeners:
- 5–7 feet wide is ideal
- 7 feet offers the best balance of comfort and structure
Once the width is right, everything else — height, strength, and plant growth — falls into place.