If snow has fallen on your winter vegetable garden, do not despair. Snow is akin to an insulating blanket and the cool-season vegetables beneath can still be harvested.
A killing frost or freeze will do the most damage to your vegetable garden in winter–not snow. Protect crops from freezing temperatures with mulch, plastic tunnels, or cold frame. Loose straw or fallen leaves will protect plants from freezing temperatures also.
If temperatures are in the high 20s or low 30s, cabbage, chard, and head lettuce and carrots, turnips, and Brussels sprouts can still be harvested–even from under a blanket of snow. Scallions and fall leeks can be harvested also–the leeks will be about the size of scallions. Onions can stay in the garden under a protective layer of mulch.
Cool season crops planted early in the fall will come to harvest in the next several weeks. (If crops have slowed down–don’t fret. Once daylight drops to less than 10 hours, cool-weather vegetables slip into a no growth mode. Growth will resume when the light each days increases in January and February.) Here are a few cool-weather crop harvest tips:
• Asparagus: Asparagus is not ready for harvest until spears are about 8 inches tall when they can be snapped off at soil level. Two-year-old roots can be harvested for 2 or 3 weeks; three-year-old roots can be harvested for 3 to 4 weeks; older asparagus beds can be harvested fro 6 to 8 weeks. Don’t cut spears smaller around than your little finger.
• Broccoli: Broccoli and other cabbage family member seedlings should be thinned to 18 to 24 inches apart to ensure full growth. Keep an eye on broccoli florets as they develop. You’ll want to harvest them when they are full but before they become heavy and floppy. It is better to cut broccoli florets a tad early and keep them in the refrigerator than to be surprised by an unusually warm winter day which will open the flowers and spoil your efforts. Once the main floret is cut, smaller florets will develop in leaf axils for further harvest.
• Chard: Chard leaves can be cut when they are about 6 inches long and still young. Don’t bother with older leaves; send them to the compost pile. Cut just what you can eat and come back later for more. Chard will keep producing as long as you avoid lifting the roots.
• Fennel: Florence fennel is ready for harvest when bulbs are about 2 inches across at the base. Don’t let fennel get much bigger or it will bolt and set seed.
• Kohlrabi: Harvest kohlrabi’s above soil bulbs when they are 2 to 3 inches in diameter. (Turnips are best harvested at about the same size.) Lift the bulbs gently or cut them off just above the soil to avoid pulling up neighboring bulbs. Don’t let bulbs grow much larger or they will become woody.
• Lettuce: Lettuce must be protected from freezing temperatures; keep the plastic tunnel handy when temperatures dip. Leaf lettuce can be harvested cut-and-come-again, just like chard. Cut the leaves you can eat just above the base and let the plant grow on. Head lettuce is ready for harvest when the head is firm. Keep excessive rain from head lettuce or it will swell up and the head will split.
• Peas: Pick snow pears before pods begin to bulge; pick snap peas before pods fully develop; pick shelling peas when the pods are plump and still bright green–and tender. Begin the pea harvest soon after the first blossoms appear–the first pods for picking will be low on the plant. Continue to pick peas every day until the harvest is finished.
Preparing for Beans
Where the soil is workable, you can prepare a planting bed for next year’s pole or runner beans. Dig a trench 18 inches wide and about 12 inches deep. Loosen the soil with a garden fork and add a 3 to 4 inch layer of aged manure or compost to the bottom of the trench. You also can add hoof and horn fertilizer or dried blood. Then fill the trench with 3 to 4 inches of soil and a second layer of compost and then the remaining soil. Mark the trench with pegs or garden flags. The site is now ready for sowing beans late next spring.
Cold Frame Tune-up
Check the seal between the lid and top of your coldframe to make sure it is tight. The frame edge can be lined with weather stripping or a strip of used carpet underpad to ensure cold air does not enter the frame.
Where temperatures are very cold, a piece of plastic sheeting can be stretched over single layer lids made of glass, plastic, or Plexiglas. Double layers of glass–or an added layer of plastic sheeting–will provide the greatest insulation.
The height of a coldframe should be just taller than the height of the tallest crop that you are growing in the frame. Always make a frame slightly taller than the crop you are growing at maturity.
A stackable cold frame will serve this purpose. Low frames are all that is needed for spring crops. But for winter growing, stackable frame units 6 to 8 inches tall all around can be used to raise the frame. A cabbage plant may require four 8-inch units. Place the sloping unit–sloping toward the South–on top. You can secure stacking frame units with pegs that fit into the unit below. Plastic sheeting, a tarp, or old carpet can be stretched around the inside of the frame to insulate and keep wind and cold from coming through the gaps.