Lay the two posts side-by-side on a flat surface, 42 inches apart. Measure 6 feet down on both posts and mark with a pencil. Roll the welded wire fencing over the posts. Starting at the top, attach the wire to the posts with the fence staples. Cut the wire with wire cutters at the 6 foot mark. Carefully turn the trellis over and lay flat. Attach the wire fencing with fence staples, again cutting the wire at the 6-foot mark.
Dig two holes, 2 feet deep and 3 1/2 feet apart. Add 4 inches of gravel and tamp. Fill with water and allow the water to soak into the soil, wetting it thoroughly.
Set the ends of the trellis posts into the holes. While your helpers holds the posts vertically, pour a bag of quick-setting cement into each hole. Add water and allow to set overnight.
Insert the soaker hose into the top of the wire trellis, allowing the end to drop across the bottom and draping the remainder over the top. Pull the female end out and attach to the garden hose.
Stuff sphagnum moss into both sides of the wire fencing. Fill the space between with a good quality potting soil. Work in 1-foot sections, adding moss and soil little-by-little. Wind the soaker hose over the top of each section before proceeding to the next. At the top, simply fold any excess hose and secure with zip ties. Cover with sphagnum moss.
Turn the water on and soak the garden wall thoroughly before proceeding.
Poke a hole in the sphagnum moss at a 45 degree angle downward and insert the strawberry plant into the soil. Tuck the moss back around the plant to secure it in place. Do not cover the crown of the plant. Plant the strawberries 1 foot apart in a grid or spiral pattern on both sides of the vertical garden wall.
Water as soon as the soil inside the trellis feels dry. A vertical garden is exposed to drying winds and may dry out more quickly than a strawberry pot or in-ground garden.
Fertilize in the spring and fall with a balanced 10-10-10 liquid fertilizer mixed in equal amounts with water.
Tuck the strawberry runners into the soil to sprout.