What to Do in the Garden in December (Cool-Climate US)

Winter protection outdoors

• Apply winter mulch (straw, chopped leaves, or other organic material) to newly planted perennials once plants are completely dormant and temperatures are consistently below freezing (Purdue Extension).
• Wrap trunks of young, thin-barked trees to prevent bark splitting.
• Mound soil about 12 inches high over roses for winter protection.
• Tie shrub stems together where heavy snow slides off roofs, and remove heavy snow loads carefully with a broom.
• Shield evergreens from winter desiccation with protective screens, and keep de-icing salt away from plantings.

Indoors and holiday plants

• Keep poinsettias and Christmas cactus in a cool, brightly lit area to extend their bloom.
• Move houseplants closer to windows as days shorten, and check leaves for dry, brown edges, a sign to raise humidity.
• Reduce watering and stop fertilizing as houseplant growth slows or stops for winter.
• Bring forced bulbs out of cold storage on schedule: they need a few weeks of warmth (around 60 F) and bright light to bloom.
• Evergreens other than pines and spruce can be trimmed lightly now for holiday greenery (Purdue Extension).

Wrap up and look ahead

• Inspect stored produce and tender bulbs for decay and discard anything going soft.
• Clean up remaining dead plant material and debris.
• Write down notes and observations for next year's garden, what worked, what didn't, and what to order in January.

Sources

Reviewed 2026-07-18. We cite university Extension, government, and established horticultural sources — and never invent pesticide rates or dangerous treatments.

• Purdue University Extension — December garden calendar (Indiana Yard and Garden) — December tasks: winter mulch after full dormancy and consistent freezing temps, trunk wraps, 12-inch rose mounding, snow-load removal with a broom, desiccation screens, holiday plant care, stored bulb checks, record-keeping

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