Up the wall and fasten it there.
How to secure plastic sheeting to ground.
If you pack tarp clips with your plastic sheeting most of these will work well for providing tie down locations.
Dig a 3 inch deep trench around the edges of your garden bed.
Smooth the plastic over the top of the ground so it comes in contact with the soil and doesn t float above it.
Leave an extra foot or two on the sides to help secure the plastic and trim any excess.
Push the edges of the plastic into the trench.
Cover the dirt crawlspace with a plastic moisture polyethylene vapor barrier.
Use your snap clamps to secure the plastic to the front and back ribs over your previous work.
Replace the soil into the trench so that the plastic is anchored down securely.
Make sure seams between your plastic sheets overlap each other then tape them down.
Allowing a little slack or at least pulling on the plastic only enough to avoid wrinkles remove the wigglewires one at a time put the outer plastic in place and tack both layers in the channel.
Hammer masonry nails through 1 by 2 inch strips of pressure treated lumber to hold the top of the polyethylene in place.
Overlap any seams and tape them.
Hold the top left corner of the first plastic sheet to the top corner of the first wall and staple it into place with a heavy duty staple gun.
And bring the plastic about 6 in.
White tape is preferable duct tape has a top layer of polyethylene wrap an old piece of greenhouse plastic around the pvc before installing your new plastic.
Drape the plastic sheeting over the frame.
Additionally at the edges of your crawl space where the soil meets the walls leave several inches of sheeting allowance.
You can easily pound a stake through the sheeting but this may lead to tearing which is why setting rocks on them is better.
Apply a polyethylene tape to the area where the pvc meets the greenhouse plastic.
Stake the plastic down with landscape fabric stakes to keep it in place.
Rocks usually work well for keeping ground sheets in place.
A so called termination strip made of wood holds the plastic in place.