I was just looking at shade cloths but the wind is such a bear! I've been considering draping shade cloth over my run and securing it with auger anchors. Has anyone tried that? I def don't want to attach the cloth to my run and have the wind carry away the whole run.
Consider using 9 mil tarps.. They are quite strong, and worth the extra cost over the inexpensive entry level tarps,, 4mil.
I had some shatex brand shade cloth with grommets. I cursed it when it ripped during a wind storm.
I hope Shatex did not hear you

,, or too offence
I'm trying to work up the intestinal fortitude to cut slits in the tarp.
Let me add my opinion here to these postings. I do get pretty strong winds in my area. I have multiple tarps (3) that cover my chicken run area. Run is between house, and fence. About 15 feet wide, by about 70 feet long. Each tarp is attached to the house, or garage structure at one end. Other end is attached to fence line. I have a steel cable that runs stretched the complete length. The tarp is attached to cable with rubber bungee cords. Each grommet gets a rubber cord to attach to cable. When winds are severe, the rubber allows for easy stretching, and grommets, and tarp do not rip.
I can post pictures of my setup , ,(don't have any at moment) but my explanation is simple.
I don't recommend cutting slits into tarp,,, unless there is a sewn in reinforcement at that spot. A slit is just an invitation for it to zipper open more than desired.
Now, to get ground anchors into hard soil. If not able to get the screw type like dog tie-outs, consider rebar lengths pounded into ground at 90 degrees to direction of pull force. If soil is too dense/hard to pound in,,, consider predrilling the ground first. I have a set of these long drills,,, although I do not need them for ground drilling by me. (soft soil)
They will drill in hard earth with no problem. You would need to keep pulling it out as drilling,,,, to remove the earth. Then pound in the rebar lengths.