Winter is coming, and for gardeners, that means thinking about protection. If you’re wondering how to cover plants for snow, you’re in the right place. A little preparation can save your favorite shrubs, perennials, and tender plants from winter’s harsh frost and heavy snow.
The goal isn’t just to keep plants warm; it’s to shield them from freezing winds, desiccating sun, and the physical damage of ice and snow load. Knowing what, when, and how to cover makes all the difference between a plant that rebounds in spring and one that doesn’t.
How to Cover Plants for Snow
This process is about creating a protective microclimate. It starts with choosing the right materials and timing your intervention perfectly. Rushing to cover too early or using the wrong fabric can sometimes do more harm than good.
Let’s break down the essentials.
Why Covering Plants is Necessary
Winter damage isn’t just about cold temperatures. Plants face a triple threat:
* Freeze Damage: Ice crystals form inside plant cells, rupturing them. This is what causes blackened, mushy leaves on tender plants.
* Frost Heave: Alternate freezing and thawing of soil can push plant roots right out of the ground, exposing them to the air.
* Winter Burn: Evergreens continue to lose moisture through their leaves (needles) in winter. When the ground is frozen, roots can’t replace that water, leading to brown, scorched foliage.
* Physical Breakage: The weight of wet snow and ice can snap branches and stems, especially on shrubs with weak structures.
A proper cover mitigates these issues by moderating temperature shifts, blocking wind, and supporting snow load.
When to Cover Your Plants
Timing is critical. Covering too early can stifle plants or create a damp environment that encourages disease.
Cover your plants after the first hard frost but before a deep snow or severe cold snap is forecast. This is usually when temperatures are consistently dropping below freezing at night. The covering goal is to trap soil’s residual warmth, not to keep the plant actively growing.
Always check the weather forecast. If you see a night predicted to be significantly colder than the recent trend, that’s your cue to act. Remember to remove covers during mild daytime periods to allow for light and air circulation.
Choosing the Right Covering Materials
Not all covers are created equal. The best materials are breathable, insulating, and allow light penetration. Here’s what to use and what to avoid.
Excellent Choices:
* Frost Cloth or Floating Row Cover (Reemay): This is the gold standard. It’s lightweight, breathes, and lets in light and water. You can leave it on for extended periods.
* Burlap: A classic, breathable material great for wrapping shrubs and trees. It protects from wind and sun while preventing heavy snow buildup.
* Bed Sheets or Blankets: Old cotton sheets or lightweight blankets work in a pinch for sudden frosts. They provide good insulation but must be removed during the day.
* Commercial Shrub Covers: These are convenient, zip-up cones or bags made from breathable fabric, ideal for small to medium shrubs.
* Straw or Pine Boughs: Perfect for covering low perennials and garden beds. They create air pockets that insulate superbly.
Materials to Avoid:
* Plastic Sheeting: It traps moisture, doesn’t breathe, and can cook plants on sunny days. If you must use it, create a tent structure so it doesn’t touch foliage.
* Heavy Tarps: Similar to plastic, they lack breathability and can crush plants under snow weight.
* Leaves (Piled Directly): A light layer is okay, but wet, matted leaves can smother plants and harbor pests. Use them in compost instead.
Step-by-Step Covering Instructions
Follow these steps to ensure you’re providing the best protection for your plants.
1. Prepare the Plant. For perennials, give them a gentle trim in late fall, removing dead foliage to prevent rot. Water your plants deeply a day or two before a hard freeze is expected. Well-hydrated plants are more frost-resistant.
2. Drive Support Stakes. For larger plants or beds, place tall stakes around the perimeter. This creates a frame that holds the cover away from the foliage. Contact between cold, wet fabric and leaves can cause damage.
3. Drape the Cover. Lay your chosen material (frost cloth, burlap, etc.) over the stakes. Ensure it reaches all the way to the ground on all sides.
4. Secure the Cover. Use rocks, bricks, or landscape pins to weigh down the edges securely. This prevents wind from getting underneath and billowing the cover off. Don’t pull it too tight; allow for some slack.
5. Add Extra Insulation (if needed). For extremely tender plants in very cold zones, you can layer materials. For example, use a frost cloth first, then burlap over top.
6. Know When to Uncover. As winter wanes, start peeking under covers on warmer days. Once the danger of severe frost has passed in spring, remove covers gradually to acclimate plants.
Special Considerations for Different Plants
Different plants have unique needs. A one-size-fits-all approach won’t work.
Young Trees and Tender Shrubs (Roses, Hydrangeas)
For rose bushes, mound 10-12 inches of soil or mulch over the base after the first frost to protect the graft union. Then, wrap the canes in burlap. For hydrangeas and other shrubs, a burlap screen stapled to stakes is often better than a full wrap, as it breaks the wind without trapping too much moisture.
Perennial Beds and Bulbs
After the ground freezes, apply a 2-4 inch layer of mulch (shredded bark, straw, or pine needles) over the bed. This prevents frost heave and insulates the roots. Avoid piling mulch directly against plant crowns, which can cause rot.
Container Plants
Containers are especially vulnerable because their roots are exposed on all sides. Your best bet is to move pots to an unheated garage or shed. If they must stay outside, group them together against a sheltered wall, wrap the pots in bubble wrap or burlap, and cover the top with frost cloth.
Evergreens and Hedges
Use burlap to create a windbreak on the windy, sunny side (typically south-west). Don’t wrap them too tightly in a solid cover, as this can cause interior needle drop. For tall hedges, driving stakes and attaching burlap as a fence is very effective.
Common Mistakes to Avoid
Even with good intentions, it’s easy to make errors. Here are the big ones:
* Covering Too Early: This delays dormancy and weakens the plant.
* Using Non-Breathable Plastic: Leads to fungal diseases and temperature extremes.
* Forgetting to Secure Edges: A windstorm can undo all your work in minutes.
* Leaving Covers on Too Long in Spring: Can promote weak, spindly growth that’s susceptible to late frosts.
* Ignoring the Root Zone: The roots are often more vulnerable than the tops. Mulching is crucial.
FAQ: Protecting Plants from Winter Frost
Q: What’s the best fabric to cover plants from frost?
A: Breathable frost cloth (floating row cover) is the best overall choice. Burlap is a close second, especially for wind protection.
Q: Can I use old blankets to cover plants?
A: Yes, cotton or fleece blankets can work well for temporary frost protection. Just remember to remove them during the day so the plant gets light.
Q: Should I water plants before a freeze?
A: Yes, moist soil retains heat better than dry soil. Water deeply a day or two before a predicted hard freeze.
Q: How do I protect large shrubs from heavy snow?
A: Gently tie loose branches together with twine to prevent splaying and breakage. For arborvitae and cedars, you can wrap them with a loose netting to hold branches in place.
Q: When is it too late to cover plants?
A: If a severe freeze has already happened and damage is visible, covering won’t reverse it. However, covering can still prevent further damage from subsequent frosts.
Q: Do all perennials need to be covered?
A: No. Most hardy, native perennials are adapted to your local climate and need only a good mulch. Focus your efforts on tender perennials, new plantings, and marginal varieties for your zone.
Taking the time to properly cover your plants is an act of faith in the next growing season. By following these practical steps, you give your garden the best chance to emerge from winter healthy and ready to thrive. With the right materials and timing, you can effectively shield your plants from the worst of winter’s bite.