A greenhouse or a shade house will not protect your garden from the bugs, it will just make it harder for the beneficial bugs to get in and help you out against the annoying pests. About the only thing that a screen house might help against might be some types of moths (hence caterpillars and grass hoppers) And caterpillars are one of the few pests that we have aquaponics safe products that we can use against them.
PVC out in the sun will get brittle and my be prone to breaking more over time. I've not had any of my water pipes on my AP systems snap due to sun or heat but I don't have any systems more than 5 years old and the water flowing through them help keep them cool. A shade structure might be better to build using fence top rail conduit.
If you have time (like 18 months to maturity) I am have really good luck with a pineapple. I just cut the top off a Dole Golden from Publix, stuck in in the gravel bed and let it go. I now have a fruit growing.
I'll be adding some grow beds this summer and plan plant some more as I buy and eat one. I should have room for 8-10 as they can be grown quite close together. By just planting a top whenever I've eaten one, they should ripen at wide intervals (and whenever one is harvested, the top gets replanted so it is an ongoing crop
I read one of his books many times some 15 years ago. The library eventually told me I couldn't check it out anymore. He wasn't much on organic gardening back then but neither was I.
David Hart said:
"IF' you live in FL....... I recomend a book called MONTH BY MONTH GARDENING IN FL by Tom MacCubbin.