I'm still in awe each time I
pass by Anna's quick
hoop experiments.
The pay off is pretty huge
when you consider how many fresh garden salads we continue to have on a
daily basis thanks to a mixture of cut pieces of rebar, PVC, and some Agribon
material.
I remember this time last
year dreaming of fresh leafy greens in a gastronomical sense of the
word.
Even though it sounds counterintuitive, Eliot Coleman's experience (and my more limited experience too) suggests that you want to use the lightest weight row cover fabric. Row covers work by trapping in heat, but that effect is counteracted if the fabric blocks winter sunlight. So, plants tend to freeze faster under heavier fabrics, unless you're someone who's willing to take the row covers off every morning and put them back on every night.
I used AG-19 on my hoops, but it looks like AG-15 is even lighter. I'm not positive whether AG-15 would be strong enough to keep from tearing in the garden, though. If you do try AG-15, I hope you'll report back!