Preparing plants outside for winter helps them survive cold, wind, wet soil, and sudden temperature swings. The right approach depends on your local climate, each plant’s hardiness, and whether it is in the ground or a container. Before the first hard frost, check your area’s expected low temperatures and identify plants that need extra protection; avoid covering everything too early, since many plants benefit from cool weather and dormancy.
What You’ll Need
- Clean garden pruners and gloves
- Mulch such as shredded bark, chopped leaves, or straw
- Frost cloth, burlap, or another breathable cover
- Stakes or hoops to keep covers off foliage, plus clips or weights to secure them
- Watering can or hose, if the soil is dry before it freezes
- For potted plants: a sheltered spot, insulating material, or a way to move them indoors
Step-by-Step
- Check your climate and plant labels. Look up your area’s typical first frost and winter low, then compare those figures with each plant’s hardiness rating. A rating describes the conditions a plant may tolerate when established; it does not guarantee survival in exposed, wet, or container-grown situations. Prioritize tender plants, young specimens, and plants exposed to wind.
- Decide which plants should stay outside. Hardy perennials, shrubs, and trees usually benefit from remaining outdoors and entering dormancy. Bring tropical and other frost-sensitive plants inside before temperatures reach their tolerance limit. Inspect plants for pests, and acclimate them to indoor light and humidity when possible. Do not put a tender plant in a heated room simply because a light frost is forecast if a cool, bright indoor space is available.
- Water the soil before it freezes, if it is dry. Water deeply around evergreen shrubs, recently planted trees, and other plants that need moisture, allowing excess water to drain. Moist soil holds heat better than very dry soil. Do not water frozen ground or leave plants sitting in waterlogged soil; saturated roots are vulnerable to damage and rot.
- Clear diseased debris, but leave healthy structure where useful. Remove fallen leaves and plant parts that show disease or harbor pests, and dispose of them rather than composting them if the disease may persist. Cut back broken or badly damaged growth with clean pruners. In many gardens, healthy perennial stems can remain until spring: they provide shelter for wildlife and may protect crowns. Avoid heavy pruning of trees and shrubs in fall unless a specific problem requires it.
- Mulch after the ground begins to cool. Spread about 2–4 inches (5–10 cm) of loose organic mulch over the root zone, adjusting for the material and local conditions. Keep mulch a few inches away from trunks and woody stems to prevent rot and discourage pests. In very cold areas, mulch helps reduce repeated freezing and thawing; it should not be packed tightly against the plant or used to bury the crown of a plant that needs good drainage.
- Protect exposed plants from wind and frost. Before a frost, set hoops or stakes around vulnerable plants and drape breathable frost cloth or burlap over them. Secure the edges to the ground so cold air cannot blow underneath, while keeping the cover from pressing on foliage where possible. Use covers overnight and remove or open them during mild daytime weather so plants can receive light and avoid overheating. Plastic can touch foliage and cause cold injury; if used temporarily, support it so it does not contact leaves, and remove it promptly in daylight.
- Insulate container plants. Roots in pots experience colder temperatures than roots in the ground. Move hardy containers to a sheltered spot out of prevailing wind, group pots together, and raise them slightly so drainage holes remain clear. Wrap the pot—not the plant—in insulating material, or sink it into the ground if practical. Move containers holding tender plants to a suitable frost-free location. Keep drainage working and water sparingly when the potting mix is dry and unfrozen.
- Check protection through winter. After storms, make sure covers remain secure and branches are not bent or broken by snow. Brush heavy, wet snow off shrubs gently if it is safe to do so; do not shake frozen branches. Check container drainage and soil moisture during extended dry spells. Remove covers and gradually uncover plants when severe frost risk has passed, following local forecasts rather than a fixed calendar date.
Common Mistakes
- Covering plants too early: Warm, damp covers can encourage soft growth, pests, or disease. Wait until cold weather is approaching or the plant’s needs call for protection.
- Piling mulch against trunks: This holds moisture against bark and can invite rot or rodents. Keep a clear gap around trunks and stems.
- Using airtight plastic over foliage: Plastic traps moisture and can transfer cold directly to leaves. Choose breathable fabric or support plastic so it cannot touch the plant.
- Pruning everything in fall: Some plants flower on old wood, and many seed heads and stems offer winter shelter. Remove only what is diseased, broken, or necessary for a plant-specific reason.
- Assuming a hardy plant in a pot is as safe as one in the ground: Container roots are more exposed to cold. Provide shelter or insulation based on the plant and your winter temperatures.
- Watering on a fixed schedule: Dormant plants use less water, but evergreens and containers can still dry out. Check the soil and drainage before watering.
Tips
- Label plants that need spring uncovering or a different pruning schedule, and note what worked after winter.
- Use loose, dry leaves as mulch only if they will not mat into a water-blocking layer; shred them or mix them with other mulch.
- For shrubs in windy sites, a simple windbreak can reduce drying without wrapping the plant tightly.
- Keep frost cloth ready where you can reach it quickly. Forecasts and sheltered garden conditions can differ, so check plants and local weather regularly.
- When uncertain, check care guidance for the exact species and cultivar. Winter protection varies substantially among plants commonly sold under broad names such as “lavender” or “hydrangea.”
Troubleshooting
Leaves look limp or dark after a frost: Do not cut them off immediately. Wait until conditions stabilize and the extent of damage is clear; healthy stems may still protect the crown. Remove dead or mushy growth later with clean pruners.
A plant is wilting despite cool weather: Check soil several inches below the surface. If it is dry and unfrozen, water thoroughly and let excess drain. If it is wet, stop watering and improve drainage rather than adding more.
A covered plant is damp or moldy: Open or remove the cover during suitable daytime weather, improve airflow, and remove diseased material. Replace an airtight covering with breathable fabric, and avoid leaving wet leaves trapped against the plant.
A pot has cracked or its roots may have frozen: Move it to a sheltered, unheated place if the plant can tolerate that environment. Let the soil thaw gradually; do not pour hot water on it. Wait for new growth before deciding whether the plant has died.
Branches have split under snow or ice: Avoid pulling or striking frozen branches. Once the ice has melted, remove clearly broken branches with appropriate clean cuts. Seek professional help for large limbs or damage near power lines.
Frequently Asked Questions
When should I cover plants for winter?
Cover frost-sensitive plants when a damaging frost is forecast and temperatures approach their tolerance. For winter-wet or cold-sensitive plants, use the protection recommended for that species and local climate.
Can I leave potted plants outside in winter?
Some can, but pots expose roots to greater cold than garden soil does. Check the plant’s hardiness, shelter and insulate hardy pots, and move tender plants somewhere frost-free.
Should I cut back perennials before winter?
Not necessarily. Remove diseased or damaged growth, but healthy stems may provide wildlife habitat and some protection. Follow species-specific advice, especially for plants that flower on old growth.
How much mulch should I use around outdoor plants?
A loose layer about 2–4 inches (5–10 cm) deep is a common starting point. Keep it away from trunks and crowns, and adjust for the material, drainage, and local climate.
Is plastic safe to use as a frost cover?
Only as a temporary cover supported so it does not touch leaves, and remove it during the day. Breathable frost cloth is generally easier to use and safer for foliage.
Do outdoor plants need water in winter?
Sometimes. Check soil during dry spells, especially for evergreens and containers. Water only when the soil is dry and unfrozen, and make sure excess water can drain.