By Augie Alvarez, Horticultural Director — Perennial Gardens Bedford
Winter in northern Westchester is serious. Zone 6b-7a means temperatures that dip to -5°F in cold winters, frequent freeze-thaw cycles through February, heavy wet snow loads, ice storms, and drying winter winds. Garden plants that are reliably hardy need no special protection; plants at the edge of their hardiness range or in stress conditions often benefit from intentional winter care. After three generations of winter garden management across Cornell Cooperative Extension of Westchester County service territory, here's what actually works — and what doesn't — for Westchester winter conditions.
Understanding Winter Stress
Plants face four distinct winter stress sources.
Cold temperature. The obvious one. Some plants are simply not hardy at our winter lows. No protection makes a Zone 8 plant hardy in Zone 6.
Freeze-thaw cycles. Our winters oscillate between hard freezes and thaws, particularly in February-March. These cycles can damage plants more than steady cold. Roots heave out of soil, bark splits, and water infiltrates tissue that then freezes.
Drying wind. Evergreen foliage continues to transpire (lose water) in winter, but frozen soil can't supply replacement water. Wind accelerates this drying. Results: "winter burn" — browning and foliage damage.
Physical damage. Heavy wet snow compresses evergreen branches below their structural limit. Ice coats branches, adding weight. Freezing rain can destroy mature conifers.
Each stress source has its own management strategy.
What Works for Each Stress
For cold temperature
Most hardiness issues are solved by matching plant to zone rather than by protection. Exception: border-hardy plants and newly-planted specimens.
Mulch application. 3-4 inches of organic mulch over root zone, applied after first hard frost but before ground freezes. Mulch moderates soil temperature, reducing freeze-thaw damage and insulating roots. Most effective protection for most plants.
Root mulching specifically. Mulch should cover root zone, not stem base. Mulch piled against stems (volcano mulching) causes rot and rodent damage. Clear the stem and expand mulch outward from there.
Bark protection for young trees. Wrap young tree trunks with commercial tree wrap to prevent sunscald (winter sun damage to south-facing bark) and rodent chewing.
For freeze-thaw cycles
Heavy mulch. Same mulch application as for cold, but depth matters more. 4-6 inches for border-hardy perennials can make the difference between survival and loss.
Avoid fall pruning. Late pruning stimulates new growth that won't harden before winter. Most pruning should happen in spring, after severe cold passes.
Delay cleanup. Leaving perennial foliage standing through winter provides natural insulation. Cut back in late winter (late February-March) rather than fall.
For drying wind (winter burn)
Burlap screens. Burlap wrapped around or staked in front of vulnerable evergreens reduces wind exposure without completely enclosing the plant. Effective for rhododendron, some azaleas, boxwood in exposed locations.
Anti-desiccant sprays. Commercial anti-desiccant products (Wilt-Pruf, Wilt Stop) create a waxy coating on evergreen foliage that reduces moisture loss. Applied in late November through early December for most reliable effect. Multiple applications through winter in windy sites.
Water deeply before ground freezes. Plants enter winter with stored water in roots and tissue. Deep pre-freeze watering (late October-early November) helps evergreens survive winter drying.
Site selection. Future plantings should consider wind exposure. Sheltered locations behind structures or established plantings reduce winter stress for borderline-hardy species.
For physical damage from snow and ice
Structural support. Tying columnar evergreens (arborvitae, certain junipers) with soft rope or deer netting prevents splitting from snow load.
Gentle snow removal. Long-handled brooms can gently remove accumulating wet snow from branches. Timing matters — remove before accumulation exceeds structural limits. Avoid shaking frozen branches; wait for thaw.
Don't de-ice with salt. Deicing salts damage plants within splash range. Alternative deicers (calcium magnesium acetate, sand, cat litter) are safer.
Prune susceptible species. Plants that routinely break under snow load (some arborvitae, overgrown yews) benefit from structural pruning to reduce mass.
Plant-Specific Winter Care
Roses
Hybrid teas and floribundas. Mulch to 12 inches at base after first hard frost. Pruning to 2-3 feet reduces wind damage.
Shrub and old garden roses. Usually hardy without special protection in Zone 7a. Mulch at base.
Climbing roses. Cane protection in exposed sites — wrap with burlap or detach from support and lay on ground covered with mulch (some gardeners).
Hydrangeas
See our hydrangea care guide for species-specific winter protocols. Macrophylla needs most protection; paniculata and arborescens generally hardy without intervention.
Rhododendron and azalea
Windbreak for exposed sites. Burlap screens on north and west sides of rhododendron in exposed locations. Anti-desiccant spray in late fall.
Mulch over root zone. 3-4 inches wood chip or shredded leaf mulch.
Boxwood
See our boxwood blight article for primary disease-management context. Winter-specific: burlap windbreaks for exposed plantings, anti-desiccant if historical winter burn has been an issue.
Perennials
Most Zone 6b-7a perennials require no special winter protection. For border-hardy species, heavier mulch (4 inches) in late November. Leave most foliage standing through winter for natural insulation.
New plantings (first winter)
Everything planted within the current year benefits from extra protection in its first winter. Heavier mulch, burlap screens for sensitive species, dedicated watering late in fall before ground freezes.
The Winter Calendar
Our standard winter preparation sequence:
Late October-early November.
- Deep watering of evergreens and recent plantings
- Leaf cleanup
- First anti-desiccant application on selected evergreens
Mid-November.
- Mulching after first hard frost
- Tree wrap on young trunks
- Burlap screens installed in exposed sites
Late November-early December.
- Structural support for columnar evergreens (netting or soft ties)
- Second anti-desiccant application in windy sites
Throughout winter.
- Monitor for damage after major storms
- Gentle snow removal from structural evergreens
- Replace dislodged mulch
Late February-early March.
- Begin cleanup — cut back perennial foliage, prune as appropriate
- Remove burlap before active growth begins
- Fertilize established plantings lightly
April.
- Replace mulch as needed for season-long coverage
- Assess winter damage and plan replacements
What Doesn't Work
Plastic sheeting over plants. Creates greenhouse effect that damages plants more than wind would. Use breathable fabric (burlap) instead.
Thick mulch piled against stems ("volcano mulching"). Causes stem rot and rodent damage. Keep mulch clear of direct stem contact.
Late fall fertilizing. Stimulates growth that can't harden before winter. Fertilize in spring or early summer, not fall.
Early spring removal of protection. Anti-desiccant, burlap, and mulch should stay in place until consistent warming, not first warm day. March freezes after February warm spells destroy plants whose protection was removed too early.
The Missouri Botanical Garden Plant Finder publishes cultivar-specific hardiness information that can inform winter care decisions.
Integration with Overall Garden Design
See our four-season estate garden guide for how winter-resilient plantings form the structural backbone of year-round garden design. Winter-hardy structure (evergreens, structural plantings, ornamental grasses left standing) reduces the need for intensive winter protection.
Containers and Winter
Container plantings face specific winter challenges beyond what in-ground plants experience.
Soil volume issue. Container soil freezes completely — in-ground soil rarely does. Plants in containers that are hardy in the ground often aren't hardy in containers because the root zone experiences much harsher cold.
Winter container strategy. Plants hardy two zones colder than your zone (for Zone 7a, plants hardy to Zone 5) can typically overwinter in containers. Anything less hardy should be planted in-ground or brought indoors.
Moving containers. Move containers to protected locations (against house walls, sheltered corners) for winter. Group containers together for mutual insulation.
Mulch container tops. A few inches of mulch on container surface reduces moisture loss and moderates root zone temperature.
Empty fragile containers. Terracotta, unglazed ceramic, and glass containers crack when their contents freeze and expand. Empty or bring indoors for winter.
Frequently Asked Questions
Should I cover my perennials with leaves?
Moderate leaf coverage (a loose few inches) provides some insulation and is ecologically valuable. Heavy compacted leaves can smother crowns and encourage rot. The goal is loose, insulating coverage, not compacted mass.
Does anti-desiccant spray work?
Yes, for the specific purpose of reducing evergreen moisture loss to winter wind. Not a cure-all. Effective on rhododendron, azalea, boxwood, and similar broad-leaved evergreens when applied before winter begins.
What about just installing deer netting instead of burlap?
Different purposes. Burlap reduces wind exposure (prevents winter burn). Deer netting prevents browsing but doesn't reduce wind. For plants that need both protections, both are appropriate.
Can I skip mulching if I don't need winter protection?
Mulching serves multiple purposes beyond winter protection — weed suppression, soil moisture retention, aesthetic continuity, soil temperature moderation in summer. Most gardens benefit from mulching regardless of winter considerations.
For winter-specific plant care questions, seasonal product availability (burlap, anti-desiccant, mulch), and winter garden consultation in Westchester, our garden center team has three generations of regional experience. Reach us through the contact page.
