Biennial vegetables are cold tolerant. They flower and set
seed in their second year, after a period of winter chilling followed by the
longer days of spring. In alphabetical order, true biennial vegetables include
beets, Brussels sprouts, cabbage, carrots, cauliflower, celery, chard, collard,
endive, kale, kohlrabi, leek, onion, parsley, parsnip, rutabaga, salsify, and
turnips.

True biennial vegetables will not bloom and produce seeds
unless they are chilled and then exposed to warmer conditions with a longer
period of light. This process is called vernalization, which translates as “to make like
spring,”

Over the winter spread a thick blanket of mulch and hay to
keep the worst of winter from killing off your selected plants