I want to have broccoli and lettuce growing well into the summer. I have tried previously but the heat just makes the lettuce bolt and the broccoli doesn't like it either. I was thinking that the use of shade cloth could help. Any opinions on this? Also, where is an appropriate place to buy some garden shade cloth and what % should I get.
The Greenhouse Megastore offers bulk shade cloth is various densities. 40% seems to be the one recommended for summer plants. I believe that is the density I have. You can cut the cloth to suit the size you need or have it custom made, which is more expensive.
I ordered a large piece around 12' x 12', then cut it to fit over my tiered green houses as well as some for the beds. I use it to shade my tomatoes, eggplants and peppers when they are first put in by hanging it over stakes or from the wire fencing. I use clothes pins to attach it! There are all sorts of possibilities! It is great stuff!
I think 87% is too dense for any fruiting vegetables- and I'm afraid the hot air temps will make your broccoli, and other cool loving plants bolt regardless of the shade. There are times we can fool Mother Nature, but usually not!
I agre that 87% is too extreme. You might try the Aluminet (sp?). It is shiny and might reflect bright light.
My garden spot is where it receives afternoon shade but I still find it difficult to keep lettuce from bolting. I'm trying a different tactic this year. Growing heat resistant/bolt resistant. We'll see...
I tried 40% shade over some tomatoes one summer. I built a hoop house from a cattle panel, then put the shade over about 8 tomato plants. The plants in the shade didn't produce as well as the plants not shaded, and they didn't seem to survive any better. I think the problem was a mix of too much shade, and TOO much summer. Even with the shade, the daytime temperatures were 90-100 (versus 100+) and the night time temperatures were still in the high seventies and low eighties. I think the shade might help when you have low humidity, or when the night time temps are cooler. When it is hot and humid, the shade just doesn't make enough difference.