One of the problems I have had over the years has been coming up with a good way to suspsend insect barrier row covers over china asters and snapdragons. China asters are terribly susceptible to aster yellows and need row covers to keep out leafhoppers which transmit the disease. Snapdragons have the bad characteristic of dropping the lower flowers as soon as they are pollinated. To get nice, long spikes, snapdragons need to be grown in a greenhouse or covered with rowcovers to keep out pollinating insects.
The row covers used for these purposes need to be suspended with some structure because if the row cover is allowed to "float" on the flowers, they can be bent or broken in high winds or when it rains. In the past I have rigged up supports using pvc pipe but have always had problems with the row cover tearing on the corners of the support. I have also had problems anchoring the row cover to the ground. I can't bury it the way some vegetables growers do because once the flowers start blooming, I need to lift the cover a couple times a week to cut the flowers.
Most often row covers are supported using little wire hoops but I didn't think these would work over a 4 foot wide bed containing plants more than 2 feet tall. I finally had the idea to adapt designs for do it yourself hoophouses. The materials I used were 2 foot sections of 3/8" rebar and 8 foot sections of pvc pipe. After squaring up the bed, I set the rebar ever 2 1/2 feet along each side of the bed and pounded them in so only about 6" stuck out of the ground. Then I bent the pvc pipe and slid each end over a rebar stake so they arched across the bed. To add stability, I joined pieces to make a 25 foot piece of pvc and attached it under the top of each arch.
The row cover can then be stretched over the entire frame. The cover is gathered and twisted together at the ends. Because I will be lifting the cover frequently, I decided to just weigh down each end with a big rock.
Seed catalogs sell fancy (and expensive) pegs for holding down row cover but I read that you can just use ground staples on top of a piece of wood.
I put all this together in a couple hours today. I wanted to set it up now so I can see how it performs before I actually put in the plants.