2 x 3/4" 10' EMT conduit
2 x 3/4" conduit connectors
zip ties
2 T-stakes
twine
plastic netting
Cut one 10' EMT conduit in half. These 2 halves make your 5' legs.
Bend 2nd 10' EMT conduit with a pipe bender. The top will be 3' long and each leg will be 3.5 ' long.
Pound your T-stakes into the ground.
Using the 3/4" connectors attach the 5' legs to the 3.5' legs. You now have a 8.5' tall trellis.
Use the zip ties to attach the trellis to the T-stakes.
Use the twine to attach the plastic netting to the trellis.
Done!
Now weave your tomatoes into the plastic netting. As they grow, continue to weave them in and out of the netting.
I buy my plastic netting here - American Nettings
Full grown tomato walls can be seen here - Tomato Walls and Me