Floating Row Covers are lightweight blankets made from spunbonded polyester or
polypropylene. there also got another name such as plant cover, plant blanket, Frost blanket, garden fabric, nonwoven fabric.
There are two basic types of Floating Row Covers:
1) frost protection,
2) insect barrier.
If the desire is to protect crops from low temperatures, be sure to purchase the
frost protection type. Floating Row Covers generally come in rolls 6 to 30+ feet wide to nearly
any length desired. Typical lengths range from 50 feet to over 2,000 feet.
Fow now, that what is low tunnels?
Low tunnels is a kind of greenhouse and it’s more lower than normal greenhouse, so we name it low tunnel, and normal greenhouse, we call it high tunnels. see the picture for low tunnels:
If you’re interested in having fresh spinach, lettuce, chard, or any other cold-hardy crop on hand late into winter or early in spring, you should build a low tunnel or two (also called a mini hoop house). These easy to build, easy to use, and relatively inexpensive structures can extend your growing season by several weeks, if not months depending on your region. Plus, they can be built in only about an hour.
If you build just one low tunnel, it will cost you about $58.00 in materials. However, you’ll be left with an extra piece of plastic sized perfectly to make a second low tunnel, which would only run you about $53.00 extra. If that sounds too costly for your tastes, you could always substitute the 1”x2”x10’s in my materials list with some cheaper wood or scrap wood you might have on hand, and that could save you about $27.00 dollars per low tunnel. Also, if you own your own electric hand grinder, you could purchase the rebar in longer lengths and cut them to size, which would save you about 42 percent, or $5.00 per low tunnel.