North American Fruit Explorers mailing list at ibiblio

[road's end farm <organic101@linkny.com>]

On Nov 24, 2007, at 12:04 PM, William C. Garthright wrote:

> Yes, you'll have to take these off between frosts.

I'm not sure just what sort of frost cover you mean. Some things (such as clear unperforated plastic) do need to be removed as soon as frost danger is over. Others don't. 

The assorted spunbonded row covers (Reemay, Kimberley Farms, Agribon etc.) that allow most light, water, and some air to pass through don't need to be removed unless/until the weather gets really hot, or to get at the crop for harvest or weeding, or if/when pollination is necessary; unless your crop is getting only barely enough light even without covers. Vegetable crops in this area are routinely kept under these for weeks at a time, to allow early spring planting, or delayed harvest in the fall, or in some cases to keep specific insects off the crop.

For some crops, these can be laid right on top of the crop; for others hoops or cages or some similar structure is needed to hold them off growing points and/or off tender leaves during high winds. (I have no idea about citrus trees, and am not sure about potatoes. Peppers need hoops. Melons need them if windy, but not if it isn't.) Whether you need hoops or a structure may depend on the amount of wind likely in the particular location, as well as the specific crop.

Two layers will provide more frost protection than one, as will choosing heavier fabrics. Both of these options will reduce light available under the cover, and increase heat buildup if the weather turns hot. Even one layer will give some protection. The manufacturer or vendor should be able to tell you about how many degrees of frost protection will be given by a specific weight of fabric (at least for short frosts; long term cold weather is another matter).

--Rivka
Finger Lakes NY; zone 5 mostly