Its harvest time and the nights are getting cooler. The average 1st frost date is October 23rd in Asheville according to the NC Extension. Brevard and Boone are October 8th, Charlotte is November 5th. For other NC locales look here or here, and for other states look here.
These are averages so a frost could come a few weeks earlier or later than those dates. Deeper valleys tend to have frost conditions earlier than the surrounding area since cold air sinks.
Most vegetables and herbs need to be harvested before the first frost, which will turn them brown or mushy. But all frosts are not created equal. A 29 to 32 degree frost may only damage the leaves, inhibiting their ability to photosynthesize. The second frost might not come for another few weeks allowing a little more harvest time. A killing frost is 28 degrees or below.
Some vegetables actually improve after a frost. These include kale, cabbage, parsnips, carrots, beets, and brussels sprouts. Frosty weather helps the starch in the root turn to sugar so they taste sweeter.
You can often winter-over these vegetables by simply covering the bed with a thick layer of straw. The mulch will help protect the plants and hold the warmth of the earth in.
When you want something fresh for dinner during the winter, you scrape the straw aside and harvest what you need. Replace the straw and you can enjoy fresh veggies all winter.
There will be more about over-wintering in a future post but a wonderful place to learn more is Elliot Coleman’s A Four Season Harvest available in our bookstore.