Biennial

Carrots are bi-annual, so collect the roots this year, keep them in sand over the winter and then replant them in the spring. Then they will go to seed.

Offered by Gus.

Mother Earth News, Sep/Oct 78
Annuals or Biennials?

The first thing you must know about each vegetable you wish to grow for seed is whether it is an annual biennial or perennial ... because each type requires slightly different treatment. (Since perennial vegetables - such as asparagus artichokes and rhubarb - are long-lived produce seed for many years running and - in any case - are best propagated from cuttings ... they will not be discussed any further in this article.) Annuals include such popular garden vegetables as peas, beans, tomatoes, lettuce, melons, squash, corn and spinach. They are the easiest types of plants to grow for seed because they mature in a single year. You just sow one generation of seeds in the spring ... and harvest the next in the fall.

Biennial vegetables - such as carrots, onions, celery, cabbage, turnips, and beets - are a little tougher. They take two years to produce seed and therefore (in many parts of North America) must somehow be "stored over" during the winter. Root cellars, cool basements and pantries, and even covered pits dug deep in the ground will all do this job nicely for most crops. Then after the danger of heavy spring frosts has passed you can replant the vegetables in your garden. If you live in a section of the country where winters are mild (coastal California for example) you can just leave them in the soil to begin with ... protected perhaps during occasional cold spells by heavy mulches and/or makeshift shelters. Most biennials will produce seed in the summer of their second year.