A Veil of Frost Protection

I started planting annuals late last week when the weather forecast showed we were clear of frost well into May.  Naturally, we have a projected low of 35° and we're under a frost warning and freeze watch.

There are a few ways to protect gardens from an unexpected frost.

The most common is to cover the plants, which is not realistic in my case--there are too many, and in areas that are too large.  With all the burlap I have on-hand, I might be able to cover 1/3 of the garden that's at risk.  Additionally, it must be promptly removed in the morning or the plants may end up baking under the covering.

In my case, I ran the watering systems on the grass for twenty minutes and the garden for the same.  Raising the humidity to nearly 100% at 45 degrees makes temperature drops difficult.  The dew point is higher, so as temperatures try to drop the water has to condense out of the air, releasing a large amount of heat and helping to protect the plants.  Additionally, the condensed water settles on the plants and soil at the temperature at which it condensed, helping to stop further drops in temperature.

The veil of frost protection woven by applying water is delicate and can be overcome if temperatures fall under 32°, but most unseasonable frosts can be overcome this way.