This year I ordered a 60% shade cloth and am currently building the frame to put it over. I used 8 landscape timbers that we had here and set them 1 ½ into the ground and am putting 2x3s at the top from pole to pole to drape the shade cloth over. The poles are set 8 apart both ways. So that puts the shade cloth about 6 ½ above the ground.
BTW I lost most of the rest of my garden which wasnt shaded as well last year. Bottom line is, what I shaded kept producing and what I didnt died.
My daughter's father-in-law (old cambodian f@rt) uses the same technique in his garden, but last year in this part of Texas.... I don't think anything helped.
/johnny
Appreciate the info...I was looking at 60-70% myself...