Grow a Squash Tunnel Using Your Raised Garden Beds

Everyone loves a good squash tunnel, especially when it’s filled with different varieties to pick from. The harvest is generous, the care is simple, and the tunnel itself becomes a living piece of garden art.

This blog dives into how to grow a mix of squash varieties in a tunnel, with a few tried-and-true tips to keep the structure sturdy, the growth balanced, and the planting effortless.

 

1. Choosing the Right Trellis Materials

Use sturdy, weather-resistant materials that can support the full weight of mature squash vines and fruit. Galvanized cattle panels, heavy-duty wire mesh, or steel arches are among the most reliable and durable options.

2. Avoid Flimsy Materials

Avoid using materials such as plastic netting or chicken wire without a solid frame, as these can sag or tear once the vines and fruit become heavy. 

3. Secure the Trellis Firmly into the Raised Beds

Raised garden beds make excellent anchor points for a trellis tunnel, keeping the entire structure stable, preventing the arch from shifting or leaning as the plants grow. Reinforcing the base with rebar or T-posts ensures long-term support through the season.

4. How Wide It Should Be

An ideal squash tunnel should be around 4–6 feet wide. Keep the width of your raised garden beds in mind, the trellis can either span between two beds or attach securely to their outer edges. A gentle curve distributes the weight evenly and gives vines plenty of room to stretch and weave naturally.

5. How Tall Should the Tunnel Be

Aim for a tunnel about 6–7 feet tall at its highest point. This height allows for comfortable movement underneath, good air circulation, and room for the vines to climb without crowding.

6. Choosing the Right Squash Varieties

Not all squash varieties are suited for trellising. Vining or semi-vining types climb naturally and adapt well to vertical growth, while bush or sprawling varieties tend to stay low and spread out. Reliable choices for a trellis include butternut squash, delicata, tromboncino, spaghetti squash, acorn squash, loofah gourds, and smaller pumpkin varieties.

7. Location and Sunlight

Squash thrives in full sun, needing at least six to eight hours of direct light each day. The trellis tunnel should sit in an open area where taller plants or structures won’t cast shade over it. A southern exposure works best in most climates, allowing both sides of the arch to catch balanced sunlight from morning to afternoon. 

8. Planting Strategy: Sow Directly in Raised Garden Beds

Sow squash seeds directly in the raised garden bed once the soil has warmed to at least 60°F (15°C), usually by late spring. Warm soil encourages quick germination and steady early growth, helping the vines establish strong roots before climbing the trellis.

9. Planting Strategy: Start Indoors and Then Transplant

In cooler climates, start seeds indoors three to four weeks before the last frost and transplant them after hardening off. Plant two or three seedlings at the base of each side of the trellis, leaving enough space for airflow and light. As the vines begin to grow, guide the strongest stems upward to form the main structure of the tunnel.

10. Training the Trellised Squash

Guide young vines gently toward the trellis with soft ties or twine until they begin to climb on their own. Once established, the plants anchor themselves naturally with curling tendrils, weaving steadily up and across the arch.

11. Continual Care

Prune overcrowded leaves to keep air moving through the canopy and to limit the spread of disease. Water deeply and consistently at the base of the plants, and lay down mulch to hold in moisture and keep roots cool. As fruits begin to form and grow heavier, cradle them in mesh slings or fabric to prevent the stems from snapping under their weight.

12. Maintaining the Trellis Structure

Inspect the trellis periodically for rust, loose ties, or sagging sections, especially midseason when vines are heavy and fruting. Reinforce as needed with additional posts or ties. At the end of the season, remove spent vines, clean the trellis, and check for wear before the next planting cycle.

13. Harvesting Tunnel-Grown Squash

Harvest squash when the skin has hardened and the color has deepened to its mature shade. Fruits grown on a trellis stay cleaner and develop a more even shape since they never rest on the soil. Use pruning shears to cut the stems, leaving a short handle attached to help winter squash store longer and keep the fruit from bruising.

Final Thoughts

A squash tunnel is a fun and striking structure to grow in the backyard. It creates a beautiful scene for photos while also bringing the bounty of the season into the kitchen, packed with nutrients in every bite. Squash is incredibly versatile, from soups, salads, and wraps to canning or even desserts.