How to keep frost at bay?

You may find you tried to stretch the growing season a little too far, or perhaps the weather experts missed the mark on the date of the final frost. A big chill is creeping up, and you’ve already used mulch and blankets as much as you can to keep the plants warm. What’s a gardener to do? Try a little emergency frost protection. Spray vulnerable plants with water to slow or prevent plant injury caused by chilling (as Florida orange growers know all too well when a rare frost threatens).

How does this work? Cold, dry air tends to draw the moisture out of leaves and from the ground; the spray of water raises the humidity levels, which in turn reduces moisture loss. Also, in order for water vapor to condense or for water to freeze, the water has to release heat, which in turn warms the plant. The plants need to be kept wet until the danger of freezing has passed; using a sprinkler system is the most practical way.