Don't let your blackberries burn
Even in the PNW it eventually gets hot enough to burn the berries. The weather here often switches from three months of below average temps to 15 degrees above average almost overnight. I finally wised up a couple years ago and bought a shade tarp. I didn't need it until now, but I'm glad I have it. I dragged it out of storage and pitched her up on the south side of my Triple Crown trellis. Here's the result.
I bought the tarp from greenhousemegastore.com. It wasn't cheap but it wasn't expensive IMO considering it has sewn-on edge tape and grommets every two feet. It's white and rated at 50%, 6' x 25'. Looks like a winner so far but the heat hasn't arrived yet. Hopefully, the wind won't take it sailing into the next county.