By Carl Wilson, Colorado State University, Horticulture Cooperative Extension
While some gardeners are thinking about putting their vegetable gardens to bed, others are planning to harvest through November. Still others are planting winter crops this fall.
It all depends on what you like to eat.
If your goal is tomatoes, eggplants, peppers and other warm-season vegetables, the first hard frost means an ending for you. In fact, tomatoes actually are best harvested and taken indoors to ripen once nighttime temperatures drop to 40 degrees.
For gardeners who like cool season fare, life is just getting interesting. Kale planted in mid-summer is just coming into maturity. Many think the crop's flavor improves after a few frosts. Plants will continue to grow and produce leaves for harvest until at least Thanksgiving. The Red Russian variety seems especially resistant to freezes.
Collards are another leafy green that seems to laugh at the cold. They will survive temperatures down to 15 degrees Farenheit. Again, cold tends to improve the flavor.
Cabbage is best stored in the garden until there is room in the refrigerator or until severe winter temperatures threaten. On heads grown almost to bursting, gardeners in- the-know twist plants a quarter turn to partially sever the root. This will prevent further growth and allows for storage in the garden until you are ready to use.
Root vegetables also will store for months in garden soil. Once the soil has cooled, many gardeners will apply a dried grass or hay mulch to prevent carrots, beets, turnips and other underground vegetables from freezing solid. Dig as needed for fresh vegetables up to the Christmas-New Year's holidays.
As for warm-season vegetables, promptly harvest the debris struck down by frosts. A thorough clearing of vegetation from the garden will help prevent the carryover of diseases into next season. Green debris nicely complements dry tree leaves in the compost bin and will produce a welcome soil amendment by next spring.
Once garden space is cleared of warm-season vegetables, consider one of two options to improve your garden soil for next year. If your soil is heavy clay, turn over the soil and leave the large clods on the surface. Winter freezing and thawing will tend to break these down saving you the work.
On both sandy and clay soils, the second option is to seed a crop of winter rye. The seed will require several waterings to germinate and get going. The plants will grow through the winter and attain a height of 12 to15 inches by spring. Their deep roots break up clay soil. Turning under the rye in early spring will add valuable organic matter to your garden.
Other crops to seed for winter are lettuce and spinach. By using a mulch or an old window supported around its sides by mounded soil, you can grow salad greens for the winter. Both lettuce and spinach germinate at temperatures as low as 40F. Cast lettuce seed on top the soil and keep moist. The seed requires light to germinate.
Interested in dill for next year? Many gardeners swear that seed is best started by broadcasting it over the soil in fall. Germination often is more successful than spring sowing.
For some vegetable gardeners, the first frost is an ending. For others it's just a beginning.
Photograph courtesy of Judy Sedbrook.
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010