December Vegetable Garden Seed-Starting & Garden Care Guide

December is the quietest month in the garden, a time for reflection, planning, and protecting what you have. In most zones, growth slows dramatically, frost is likely, and sowing is limited. But in mild climates, winter greens can still be planted, and soil preparation now will give you a head start in spring. This month is about maintaining what’s already in the garden, protecting beds, and planning for the year ahead.

Table of Contents

Zone-by-Zone Guide for December

Listed by USDA Plant Hardiness Zones, warmest zones first:

Zone 11

(Where the annual low temperatures stay above 40°F / 4°C.)

Direct-sow cool-season vegetables: lettuce, spinach, arugula, mustard, and Asian greens.
Plant garlic and shallots.
Sow carrots, beets, radishes, and scallions.
Transplant hardy brassicas such as broccoli, kale, and cabbage.
Mulch lightly to retain soil moisture.
Water as needed during dry spells.
Continue feeding container crops and tender perennials.

Zone 10

(Where the annual low temperatures can reach 30°F / -1°C.)

Plant garlic and shallots early in the month.
Direct-sow leafy greens and root crops in mild areas.
Transplant brassicas for winter harvest.
Mulch beds to conserve moisture and moderate soil temperature.
Use row covers if temperatures dip unexpectedly.
Harvest remaining late-season crops.

Zone 9

(Where the annual low temperatures can reach 20°F / -7°C.)

Plant garlic and shallots if not already done.
Protect existing winter greens with mulch or row cover.
Harvest carrots, beets, radishes, and leafy greens as needed.
Prepare soil for early spring sowings.
Avoid new sowings except in protected areas.

Zone 8

(Where the annual low temperatures can reach 10°F / -12°C.)

Focus on winter protection: mulch beds, cover tender crops, and monitor irrigation.
Plant garlic and shallots early in the month.
Harvest remaining root crops and winter greens.
Prepare garden beds for frost and snow.

Zone 7

(Where the annual low temperatures can reach 0°F / -18°C.)

Protect overwintering crops with row cover or cloches.
Harvest remaining vegetables and greens.
Plant garlic if soil allows early in the month.
Mulch beds heavily to insulate soil.
Clean up spent summer crops.

Zone 6

(Where the annual low temperatures can reach -10°F / -23°C.)

Focus entirely on protection and soil care.
Harvest hardy greens and root crops as available.
Mulch beds heavily to prevent frost damage.
Use cold frames or row covers for overwintering crops.
Plan early spring sowings and garden repairs.

Zone 5

(Where the annual low temperatures can reach -20°F / -29°C.)

Garden activities are primarily maintenance and protection.
Harvest remaining crops.
Mulch beds deeply to conserve warmth and moisture.
Protect perennial vegetables and fruit trees.
Prepare soil for spring planting.

Zone 4

(Where the annual low temperatures can reach -30°F / -34°C.)

Focus on winter protection.
Mulch all beds.
Use cold frames or hoop houses for any overwintering crops.
Clean up garden debris.
Prepare tools and plan for early spring.

Zone 3

(Where the annual low temperatures can reach -40°F / -40°C.)

Garden is dormant.
Apply heavy mulch to all beds.
Protect perennials and storage crops.
Store tools and supplies.
Plan next season while observing winter conditions.

December Winter Transition: Looking Ahead

December is the quietest month in the garden, a time for observation, protection, and preparation. In most regions, the garden is largely dormant, but winter greens and hardy crops in mild climates can still be maintained. Mulch beds, protect perennials, and check irrigation for container plants. This is also the perfect month to plan next year’s garden, repair tools, and organize seeds. By tending carefully now, you set your garden up for a strong, productive start in January and beyond.