How to Keep Outdoor Plants Alive in Winter

Keeping outdoor plants alive through the winter can seem daunting, but with some planning and care, even cold-sensitive plants can survive the colder months. Here are tips on how to help outdoor plants, trees, shrubs, and gardens survive the winter.

Choose Winter-Hardy Plants

The easiest way to keep plants alive in winter is to select varieties that are naturally resilient to cold temperatures. Some plants to consider include:

Trees

• Evergreens like pine, spruce, and fir trees
• Deciduous trees like maple, birch, oak, and beech trees

Shrubs

• Boxwood
• Holly
• Juniper
• Rosemary
• Lavender

Perennials

• Ornamental grasses
• Russian sage
• Sedum
• Chrysanthemum
• Asters

When selecting plants, check their USDA Hardiness Zone rating and choose options rated for your zone or colder. This helps ensure they can withstand your area’s lowest temperatures.

Provide Winter Protection

For plants less hardy to winter, provide protection to help shield them from harsh winds and freezing temperatures:

Mulch Well

• Apply 2-4 inches of shredded bark, compost, leaves, or other organic mulch around the base of plants.
• Mulching insulates plant roots and prevents frost heaving.
• Continue mulching after the ground freezes to maintain insulation.

Wrap or Cover Plants

• Wrap shrubs, vines, and tree trunks with burlap or other fabric.
• Place protective waxed paper or cardboard cones around vulnerable shrubs.
• Cover low-growing perennials with a layer of pine needles or straw.
• Protect container plants by moving pots together and surrounding with bubble wrap, bags of leaves, or straw bales.

Add Row Covers

• Drape lightweight row cover fabric over plants and secure the edges with stones, bricks, or garden staples.
• The fabric traps radiant heat from the soil and provides a few degrees of frost protection.

Build Shelters

• Drive stakes around tender plants and wrap with burlap, cardboard, or tarps to create a shelter.
• Build small cold frames over low-growing perennials using boards, PVC pipes, and plastic sheeting.

string Lights

• Drape strings of outdoor-safe incandescent lights over trees, shrubs, and trellises to provide extra warmth.
• The light bulbs give off a small amount of heat.

Water Well Before Freeze

Plants need moisture through winter. Water thoroughly before ground freezes:

• Deeply water trees, shrubs, and perennials in fall. This helps saturate surrounding soil.
• Water again after mulching to moisten mulch and soil underneath.
• Stop watering most plants after hard freeze so roots don’t get damaged if water expands when freezing.
• Water garlic, onions, and other overwintering vegetables under mulch throughout winter.

Prune Carefully

To avoid winter damage:

• Prune spring-blooming shrubs/trees right after flowering since flower buds develop the previous season.
• Prune summer-blooming shrubs/trees in late winter before new growth emerges.
• Cut away dead or damaged branches to prevent decay and disease.
• Avoid heavy pruning and fertilizing late in growing season that can stimulate tender new growth.

Manage Fallen Leaves

Take care when removing or keeping dropped leaves:

• Rake excess leaves away from plant crowns to prevent moisture buildup and rotting.
• Leave some leaf litter under shrubs/trees as winter mulch if it’s not overly thick.
• Remove diseased leaves and leaves of invasive weeds to help control pests and weeds.
• Shred leaves with mower and leave as mulch or add leaves to compost pile.

Check Drainage

Excess moisture can damage plants during winter freeze-thaw cycles:

• Clear eaves troughs and downspouts to prevent water pooling at foundations.
• Ensure proper drainage away from structures and beds.
• Avoid piling snow against shrubs or beds.

Wait to Cut Back Perennials

Leave perennial stems and seed heads intact for winter:

• Standing perennial foliage traps insulating snow, providing protection.
• Seeds provide winter food for birds.
• Cut back dead perennial stems in spring to allow new growth.

Exceptions:

• Cut back diseased stems/foliage anytime to prevent spread.
• Cut back lavender, penstemon, and other tender perennials in fall.

Protect Trees from Rodents

Prevent rodent damage:

• Wrap tree trunks from bottom to lowest branches with 1⁄4 inch mesh hardware cloth. Secure with landscape staples.
• Apply non-toxic squirrel or rodent repellent around bases of trees.
• Keep trees healthy with proper water and nutrients to help withstand minor damage.

Check Winter Protection

Monitor plant protections and make adjustments as needed:

• After heavy snows and winds, check supports and shelters are still intact. Resecure coverings as necessary.
• During dry periods, sweep snow away from evergreens to prevent desiccation damage.
• Remove winter coverings in early spring as temperatures start warming.

Frequently Asked Questions About Outdoor Plants in Winter

How do I know which plants need winter protection?

Plants more prone to winter damage include:

• Tropical or subtropical plants like hibiscus, palms, bananas, and citrus.
• Herbaceous perennials like dianthus, bee balm, coral bells, and butterfly bush.
• Broadleaf evergreens like rhododendrons, camellias, southern magnolias.
• Container plants.

Check plant hardiness zone ratings and ask your local nursery for advice. Providing protection is recommended if you’re unsure.

When should I start winterizing outdoor plants?

In fall, begin preparing plants by:

• Mulching garden beds – Late October to November
• Wrapping trunks, stems, pots – Late October to November
• Moving containers together – November
• Building shelters – Late November
• Applying rodent protection – Late November

Do this well before the first expected frosts in your area.

What is the best winter mulch?

Use loose, organic materials like:

• Shredded bark or wood chips
• Compost
• Chopped leaves
• Straw or pine needles

Avoid matting, dense covers like sawdust or hay that can suffocate plants. 2-4 inches is ideal.

Should I prune before winter?

Limited pruning in late fall prepares plants:

• Remove dead/broken branches.
• Prune early spring bloomers right after flowering.
• Clean up disease/insects.
• Avoid heavy pruning that stimulates late growth.

How can I prevent rabbit/mouse damage?

Deter nibbling rodents by:

• Wrapping trunks with 1⁄4 inch mesh screens.
• Applying natural repellent sprays.
• Providing alternative foods like brush piles.
• Keeping plants healthy to withstand minor damage.

When do I remove winter protections?

Uncover plants in spring after the last frost when nighttime lows stay above freezing. Watch the weather forecast.

Can I do anything for a plant damaged by winter?

• Water well when growth resumes.
• Apply balanced granular fertilizer early in growing season.
• Prune away deadwood, shaping the plant.
• Scratch away mulch from base if stem/crown seems damaged.
• Be patient – some plants just need time to recover.

Conclusion

Caring for outdoor plants through harsh winters takes some effort, but is very worthwhile. A few simple preparations like mulching, wrapping, and pruning enable cold-sensitive plants to survive freezing temperatures. Select winter-hardy options and provide protective measures in fall through winter. Monitor protections during the season and remove them come spring. With proper care, your treasured trees, shrubs, perennials and more can thrive despite the cold and greet spring with vigor.