We're building a garden in central Texas, zone 8a/b, it varies every winter. In the summer we get triple digits temps in July-August, but that's not just from the sun. We're on Edwards Plateau, which means the ground here is almost bare of grass. There are some trees, but due to overgrazing, there's barely anything covering the soil and it all gets very very hot in the sun, the entire area.
In the winter, we get freezes maybe a total of 5 times, +/-, and once or twice it goes below 20. I've never seen it go below 10. We've had our first snow since about 2005 this winter, and still our friends said their winter veggies took the cold just fine, without any cover or protection.
Right now we're debating whether to install permanent shade cloth in our garden, since it could both keep the garden cooler in the summer and hopefully warmer in the winter. Has anyone had experience with permanent shade cloth below 30 latitude? I stumbled upon aluminet shade cloth which reflects a percent of sunlight off, keeping the garden even cooler in the summer. But what about in the winter?
Our garden is fairly tall, so it's gonna be inconvenient to have a removable shade cloth. It'd be much better if we could have a permanent one.
I see what you're saying, but I don't know that I would want to block any winter sunlight, even in Central Texas.
If it's permanent and relatively high up, what about angling the cloth? If the shade cloth sloped about 30 degrees, with the Northern side at the lowest point and the Southern side at the highest, you may get the best of both worlds. Taking more cloth to the side of the garden the wind blows from (should generally be the North or West where you are, though local topography counts), you could get the direct sunlight in winter, plus the warmth generated by a dark colored shade cloth. In the summer with the sun directly overhead, you could get the shade from the cloth while still allowing a breeze over your garden.
Might be kind of a pain, but for a more permanent structure like you're describing, it might be worth considering.
As for materials, I like wooden or galvanized metal fenceposts, and aluminet shadecloth. If you use wood be careful about finishes, if you use metal, same thing. Don't want to start adding toxic gick to your garden soil. Where you plant under the shadecloth, taking advantage of microclimates of light exposure, would make a difference. Your tomatoes would probably thrive at the edges of the shade, while your lettuce and asparagus would probably be perfectly happy at the center.
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