Tunnel Vision

It’s that myopic time of spring when the warmth and sturdiness of my low tunnels envelopes my thoughts, especially on brisk and stormy days. I suffer from tunnel vision.

We have been using low tunnels since 2004 in various applications, necessitated by the move from zone 8 to zone 4. At first, we secured the schedule 40 PVC to the outside of our 2×8 raised beds, with soft but beautiful copper conduit fasteners. Then, when we moved here and went in-ground, we hammered rebar into the ground and thread the PVC into the rebar. Now we are back to raised beds and our first attempt last spring with low tunnels for our tomatoes was met with disappointing results: despite the tunnels the frost still found its way inside and took out many of the plants.

Now it could be the lifespan and quality of the home improvement store plastic (I hope to invest in actual greenhouse plastic for next growing season), but it is likely also the way we tried to seal them. While frost can find its way into my brassica low tunnels without much worry, if I am to successfully get back to transplanting tomatoes in late April, I really need to dial in how we secure our low tunnels. So this spring we are working with a slightly modified design and new materials: low tunnel clamps and metal EMT conduit instead of PVC.

I put together this video to share with you our new approach. This is very much a real time learning process, and I expect we may make adjustments to refine this. One thing we toyed with was putting a stake in the ground and stringing parachute cord up and over both sides to really lock down the side walls so no air can penetrate. I will continue to share and modifications and the results with you as we head into April, but so far we are really happy with the strength and durability of this new design. Hope you find inspiration in these videos and think about ways you can add weeks to your spring growing season too!

And, here is a video of how I setup low tunnels for our in ground beds for the first five years here:

You might also like:

Low Tunnel Guide: Selecting + Setting Up Low Tunnels to Spring Ahead Fall Garden Guide November Monthly Task List