Wednesday, April 24, 2013
Frost Not Fog
Sometime in May we will see our last frost. One can never be sure exactly which is indeed the last but June first is generally recognized as the date to begin safely setting out tender plants. Tubs, buckets and tarps cover plants that cannot grow here without protection. Part of the problem springs from catalog descriptions. When they list a lily as hardy to zone 4, they fail to mention that frost protection is absolutely essential. It took several consecutive years of watching a Lily Regal burn black to the ground from frost before I realized that the plant needed help to survive here.
The weather forecast for last night did not guarantee frost. We decided to lug out the tarps and buckets to cover some plants. A predawn look outside suggested the presence of fog. Still the moisture visible above the ground did not look exactly right for fog. A quick trip outside to the thermometer showed the air temperature right at the freezing mark. A second trip outside with shoes proved that the white on the grass was frost not dew. The white stuff in the air is solid rather than liquid. Instead of air filled with protective tiny dots of moisture we had air filled with tiny grains of ice. This is not a common occurrence here. Now that the sun is up we will venture out to see how the uncovered plants handled the frozen mist.