Emerald Cedar Fall & Winter Care Guide

How to Keep Your Cedars Green, Healthy, and Protected Through the Winter

Emerald cedars (Thuja occidentalis ‘Smaragd’) are a popular evergreen choice for hedges and privacy screens in Ontario gardens. But as temperatures drop, proper fall preparation is key to keeping your cedars green and thriving through the cold months.

Here’s a complete guide on how to prepare your Emerald Cedars for winter — from watering and pruning to wind and sun protection.

Deep Watering Before the Ground Freezes

Before the first frost, give your cedars a deep, thorough watering.

This helps the root system store enough moisture to survive the long, dry winter.

Once the soil freezes, watering becomes ineffective — so aim for early to mid-November.

Tip: Stop watering once the ground is frozen to avoid ice buildup around the roots.

Protect from Winter Wind

Cold, dry winds are one of the biggest threats to Emerald Cedars.

They can draw moisture out of the foliage, leading to brown or burnt leaves (a condition called winter burn).

How to protect:

• Wrap exposed sides with burlap or landscape fabric.

• Install wooden stakes to form a simple frame and attach the fabric securely.

• Avoid wrapping the tree too tightly — good airflow prevents mold and rot.

Guard Against Winter Sun

Snow reflection and bright winter sunlight can cause sunscald on the south or southwest side of the trees. To prevent this, use light-colored burlap or shade cloth to reduce sun exposure. This simple step helps your cedars maintain even color and avoid leaf burn.

Minimal Pruning

Limit pruning in fall to only dead, damaged, or diseased branches.

Heavy pruning stimulates new growth, which won’t harden before frost and may get damaged. Save shaping and hedge trimming for spring.

Stop Fertilizing After Late September

Avoid applying fertilizer in late fall. Nutrients encourage soft new shoots that are vulnerable to cold damage. Let your trees naturally slow down and prepare for dormancy.

Insulate Roots and Containers

If your cedars are planted in the ground, add a 2–3 inch layer of mulch (such as wood chips or pine bark) around the base to protect the roots. For potted cedars, move them to a sheltered location — near a fence, wall, or under a covered porch. Wrap the pot with straw, burlap, or foam insulation to prevent roots from freezing.

Post-Winter Care

When spring arrives and the snow melts:

• Remove any protective wraps.

• Trim off brown or frost-damaged tips.

• Apply a balanced slow-release fertilizer to support fresh, green growth.

Final Thoughts

Taking the time to properly prepare your Emerald Cedars in fall ensures they stay vibrant, upright, and healthy all year round.

With just a few simple steps — deep watering, wind protection, and insulation — your cedars will reward you with lush green beauty come spring.