Dec 142007

Agribon AG-19 floating row cover in action

If you’re growing organically, floating row cover is practically indispensable for insect protection, and as frost protection, it’s an easy, inexpensive way to extend the season at both ends. It’s made of spunbond polyester, a porous fabric that lets rain through just fine, and comes in different weights for different applications. Weights range from the ultralight, for use as an insect barrier only (it doesn’t do much against cold), to super-heavy, for frost protection up to around 8°F (-13°C). There is a protection trade-off: the heavier, the less light transmission. I’ve been getting by with just one weight, the medium-light AG-19 from the Agribon line, which provides up to 4°F of frost protection, and 85% light transmission. With Agribon’s heaviest, AG-70, only 30% of the light gets through. The edges are typically buried or weighted (heavy rocks work) against the wind. The lighter weights can be supported by most transplanted seedlings (leave it loose enough to accommodate growth), and heavier stuff is no problem for mature plants in fall (that’s the “floating”). For seedlings, letting the cover touch leaves can allow cold burns, especially if the fabric gets damp and then freezes (this can be fairly damaging, but I haven’t found it to be fatal so far). In this case, you can stick short, non-pointy stakes every few feet to keep the cover up. I use Agribon because it’s the only brand I’ve found in smaller bulk quantities (e.g. 1000′ roll) where I am in Canada, and it’s worked great, but there are other brands of floating row cover, like Reemay and Agrofabric, which probably perform the same. (In the photo, we’re covering mid-season squash transplants to protect them from cucumber beetles.)