December Vegetable Garden

St. FrancisAs winter weather sets in early this year–just about everywhere, now is a good time to update your garden records from last season and review your garden design. What worked and what can be improved this coming growing season? Now is the time to plan layout changes for the garden and begin mapping our crop rotations and successions for the coming year.

The spring seed catalogs have started arriving so this is also a great time to prepare seed and plant orders for spring. Plan a continuous harvest for the coming year and order your seed accordingly.

Here are some things you can do now–in December:

 Plant. Plant witloof chicory roots in pots of sand and light soil mix and place them in a dark place at about 45ºF. Harvest young shoot as they appear.

Cabbage. Near the end of the month start seeds of cabbage and hardy lettuces indoors. In warm winter regions you can sow hardy and half-hardy cool-season plants such as lettuce and cabbage-family crops in the garden or under cloches. Be patient, crops grow slowly during short winter days. (There is no growth when the day light is less than 10 hours. Don’t expect new growth until mid-January.)

Tomatoes (yes, tomatoes). Tender vegetable seeds such as tomatoes, peppers, and eggplants that require 12 weeks or more indoors can be started late this month.

Asparagus, artichokes and rhubarb. These perennial crops can be set out in the perennial section of the garden this month or next. Place perennials at the edge of garden where they can produce for several years without being disturbed. Other perennials include horseradish, sage, mint, and rosemary.

Herbs need protection. Cover herbs still in the garden such as marjoram and rosemary with cloches and insulate them with a covering of leaf mulch. Divide and transplant potted or bare-root perennial herbs.

 Late apples and fruits. Finish picking late apples and persimmons.

Bare root season. Plant bare-root fruit trees. Prune back newly planted apple and other fruit trees immediately after planting reducing side-shoots to about one-half. Insert tree stakes before planting and make sure newly planted trees are secure. Water new trees deeply and add a fresh layer of mulch after planting. If you are not planting until spring, heel in trees or store in a frost-free shed keeping the roots moist.

Pruning time. Prune established apple and pear trees. Do not winter-prune cherries, damsons, peaches, or plums. Prune out broken, dead, or diseased branches and crossing branches. Make sure tree stakes are held firmly in place. Apply dormant oil to control over-wintering pests and disease.

General garden clean-up. Clean up parts of the garden not being used. Clean up dropped fruit and leaves. Compost leaves and fruit not affected by pests or disease. Place mouse guards, tree wraps, hardware cloth or chicken wire around tree trunks to protect them from rodents, rabbits, and deer this winter. Paint the lower trunks of young trees to prevent winter sunscald. Before the soil freezes mulch trees in a ring 8-12 inches from trunk.

Remove nests of tent caterpillars and cocoons attached to branches with a stiff brush or broom. Save the egg masses of the praying mantis. Learn to distinguish between the cocoons of both. On a mild day, apply dormant-oil spray to smother scale and aphids.

Maintenance. Place compost and leaf mulch on vacant part of the garden. Check windbreaks, mulches, and other winter protection before and after storms. Install burlap screens and add mulch if necessary. After storms remove broken branches from orchard trees and check the weight of snow still on branches. Water trees and the garden in dry winter regions. Make sure tools have been cleansed, sharpened, and stored in a dry place. Coat the metal part of tools with a light oil to prevent rust. Wooden handles can be painted a bright color to make them easier to find. Store tomato, bean, and other poles under cover. Store hose, coiled and shut off garden faucets. Check your outdoor storage areas for leaks.

Berries and grapes. Prune black currants, gooseberries, raspberries and brambles after a hard frost. Pruning can continue until late winter. Cut blackberry and hybrid berry canes that fruited this year back to soil level; tie newly formed canes to supports. Prune established black currant bushes by removing old shoot from the center. Shorten the lead shoots of gooseberries and red currants by half and side shoots to 2 inches. Remove all weak shoots. After pruning, apply a mulch of well-rotted manure or compost.

• Prune grapes as soon as they are dormant; remove one third to one half of the old wood and thin out undergrowth. Prune old grapevines severely so that they flourish next season.

Strawberries. Select strawberry beds now and work in plenty of compost. You can start a new bed with the strongest runners from old strawberry plants. A strawberry bed should be good for three years; even so start a new bed each year. Mulch existing beds with chopped leaves.

Greenhouse and cold frame. Clean, disinfect, and ready the greenhouse for winter. Check insulation to make sure the greenhouse can maintain the minimum temperature. Clean the glass to allow for the greatest winter light. Clear gutters before the first storms. Ventilate the greenhouse on mild and warm days; lack of air movement can encourage diseases. Gradually give plants less water so that they will better tolerate low temperatures; disease will also be less of a problem. Check plants regularly to pick off any dead or dying leaves before they start to rot. Toward the end of the month in less severe winter regions, you can start seeds of many spring plants that can go into the cold frame or into the garden in February and March. Witloof chicory and rhubarb can be started this month for harvest in spring. Onion seed, cabbage, cauliflower, broccoli, leaf lettuce, mustard, radish, and spinach can be sown in the cold frame now.

Container gardens. Move tender container plants indoors or into cold frames for winter. Half hardy container plants can go into the cold frame; sink clay pots with plants into the ground. Shallow containers should be sheltered away from frost and freezing weather. Set containers up on low supports so that they drain freely. Check these plants regularly. Remove spent plants from containers and compost; clean containers and store for winter. In mild regions, move container plants away from eves into sheltered positions. Begin to plant container vegetable planting for next year; order seeds as necessary.

Compost. Turn the compost pile with a fork and water to speed winter disintegration. You can build a compost pile of leaves with a pen of wire or boards as small as 3 or 4 feet across and 4 or 5 feet high. Place and pack leaves in pen in layers 1 foot thick; add a few shovelfuls of aged cow or horse manure to each layer. Separate layers with 1 inch of garden soil. Keep the pile moist not wet and turn it every 2 or 3 months.

Soil preparation. Turn under the last of the vegetable remains. Test soil. If acid, add a layer of lime. If lacking in nutrients add ground phosphate rock, granite dust or greensand to the garden by broadcasting these rock powders over the soil. Newly broken ground can be left rough through the winter; rain and frost will work the rock powders into the soil. Now is a good time to incorporate compost and green manure into the soil. It will blend in with the soil over winter. Rotary till or spade the material into the garden soil and let sit on the rough surface until spring. Add well-rotted manure to the area or trenches where you will plant next year’s runner beans.

Watering. Don’t depend on winter rains to water the garden. Check the soil frequently to determine whether or not it needs more water.

Regional gardening suggestions for December:

These suggestions are divided into 4 major geographical areas: North and East and Midwest (zones 2 in the northern most areas to 6 along the coast), the South (zones 7 in the north to 10 in the far south), the Southwest and California (zones 7 in the coolest areas to 11), and the Northeast (zones 5 in the highest elevations to 8 along the coast).

North and East and Midwest. Work compost and green manure into beds. Turn under last years beds. Add lime to soil if it is acid. Remove tent caterpillars nests and cocoons. Sow cool-season crops in the cold frame.

South. Plant cool-season crops such as beets, broccoli, carrots, cabbage, endive, Asian greens, kale, kohlrabi, lettuce, mustard, onions, parsley, peas, radishes, spinach, and turnips. Strawberries can be planted in some regions. Plant Rhubarb now.

Southwest and California. Perennials such as asparagus, artichokes, horseradish, and rhubarb can be planted. Make new strawberry beds. In mild to warm winter regions you can plant: beets, chard, cucumber, broccoli, Brussels sprouts, carrots, leaf lettuce, leeks, green onions, parsley, potatoes, radishes, rutabaga, spinach, tomatoes, turnips. In frost-free regions, plant cantaloupes, eggplants, muskmelon, peppers, and tomatoes. Divide and reset herbs. Divide chives.

Northwest. Cool-season winter vegetables can still be planted in cold frames that maintain a temperature of greater than 50ºF; growth will be slow. Begin planning next spring’s garden. Plan crop locations, rotations, and successive plantings for next year.

Harvest in December. Dig and harvest root crops stored under mulch as needed. Root crops such as carrots, parsnips, and salsify that come out of the garden can be stored in a cool basement until you need them. If the ground does not freeze sunchokes, carrots, parsnips, rutabaga, turnips, and other root crops can spend winter underground.

• Brussels sprouts, cabbage, chard, collards, and kale harvested now will keep for weeks if stored in a cool basement or root cellar. To enjoy spinach, winter lettuces, and spring cabbage all winter, cover the plants with a plastic tunnel or cloche. Bend the leaves of cauliflower over the curds to protect them from frost damage.

Seed saving. Seeds from non-hybrid plants can be saved from the garden for planting next year. Thoroughly dry seeds then label and store them in a closed jar in a cool, dry place.

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