How to Plant a Hedge

The Value of a Well-Planted Hedge

A properly planted hedge is one of the most valuable additions to any Northumberland County landscape. Hedges provide privacy, block wind, reduce noise, define boundaries, and create habitat for birds and beneficial insects. Whether you're looking to screen a neighbour's view, create a living fence, or add structure to your garden, the success of your hedge starts with proper planting.

The techniques in this guide apply to formal clipped hedges and informal natural hedges alike. Follow these steps, and you'll establish a hedge that thrives for decades.

Choosing Your Hedge Plants

Western Red Cedar (Thuja plicata)

The most popular hedge choice in Northumberland County, Western Red Cedar (also called Thuja Green Giant) grows 3-5 feet per year once established. It maintains rich green colour year-round and tolerates heavy pruning.

Growth rate: Fast (3-5 ft/year)

Mature height: 40-60 feet (prunable to any height)

Spacing: 3-4 feet apart

Best for: Privacy screens, windbreaks, formal hedges

Eastern White Cedar (Thuja occidentalis)

Native to Ontario, Eastern White Cedar (arborvitae) is slower-growing but extremely hardy. It's ideal for smaller properties and lower hedges. 'Emerald' and 'Techny' are popular cultivars.

Growth rate: Moderate (1-2 ft/year)

Mature height: 15-30 feet (prunable)

Spacing: 2-3 feet apart

Best for: Medium hedges, foundation plantings, deer-prone areas

Privet (Ligustrum)

Privet creates dense, formal hedges that tolerate shearing well. It's deciduous but holds leaves late into fall. Common privet and Cheyenne privet are hardy in our zone.

Growth rate: Fast (2-3 ft/year)

Mature height: 10-15 feet

Spacing: 2 feet apart

Best for: Formal clipped hedges, medium heights

Yew (Taxus)

Yews offer dark green foliage and excellent shade tolerance. They're slow-growing but create the most elegant formal hedges. Very long-lived when properly sited.

Growth rate: Slow (6-12 inches/year)

Mature height: 10-20 feet (prunable)

Spacing: 2-3 feet apart

Best for: Formal gardens, shade-tolerant hedges, historic properties

Other Options

• Hemlock (Tsuga): Shade-tolerant, soft texture, moderate growth
• Japanese Barberry: Deciduous, colourful foliage, good for security hedges
• Serviceberry (Amelanchier): Native, edible fruit, informal hedge
• Winterberry Holly: Native, deciduous, spectacular winter berries

Spacing Calculations

Proper spacing is crucial for hedge success. Too far apart leaves gaps; too close creates competition and disease problems.

Spacing Guidelines by Goal

• Single row, dense screen: Space at 75% of mature width (e.g., if plant spreads 6 feet, space 4.5 feet apart)
• Single row, formal clipped hedge: Space slightly closer, at 60% of mature width
• Double row (extra dense): Stagger plants in two rows, each row at standard spacing

Calculating Number of Plants

Measure your total hedge length in feet, then divide by spacing distance. Round up to the nearest whole number.

Example: 50-foot hedge, plants spaced 4 feet apart: 50 ÷ 4 = 12.5 → Order 13 plants

Always order 10% extra to account for occasional losses or imperfections.

Planting Steps

Step 1: Site Preparation

Clear the planting line of grass, weeds, and debris. Mark the exact line with stakes and string. If replacing an old hedge, remove all roots to prevent disease carryover.

Test drainage by digging a hole and filling it with water. If water remains after 4 hours, improve drainage or choose different plants.

Step 2: Soil Preparation

Dig a trench the full length of your hedge. Width should be 2-3 times the root ball diameter; depth should match root ball height. In Northumberland County's clay soils, wider trenches improve drainage and root establishment.

Amend excavated soil with 30% compost. For very poor soils, consider replacing entirely with quality topsoil mix.

Step 3: Planting

Remove plants from containers and loosen any circling roots. Set plants at the same depth they grew in the nursery—never deeper. The top of the root ball should be level with or slightly above grade.

Space plants according to your calculations, stepping back frequently to check alignment. A crooked hedge is difficult to correct later.

Backfill with amended soil, firming gently to eliminate air pockets. Create a shallow basin around each plant to catch water.

Step 4: Mulching

Apply 3-4 inches of shredded hardwood mulch in a 3-foot wide strip along the hedge line. Keep mulch 2 inches away from plant stems to prevent rot.

Mulch suppresses weeds, retains moisture, and moderates soil temperature—critical for establishment success.

Step 5: Watering

Water thoroughly immediately after planting—at least 5 gallons per plant. This settles soil around roots and eliminates air pockets.

Initial Care: The First Year

Watering Schedule

The first year is critical for root establishment:

• Weeks 1-4: Water deeply twice weekly (1 inch of water)
• Months 2-3: Water deeply once weekly
• Months 4-6: Water every 10-14 days if no rainfall
• Fall: Water deeply before ground freezes

In Northumberland County's variable climate, adjust based on rainfall. Check soil moisture 4 inches deep—if dry, water.

Fertilizing

Wait until the second growing season to fertilize. Young roots are easily burned by excess nutrients. In year two, apply a balanced slow-release fertilizer in early spring.

Weed Control

Keep a 3-foot strip along the hedge weed-free. Weeds compete for water and nutrients when plants are establishing. Hand-pulling is safest; if using herbicides, shield plants with cardboard.

Pruning Timeline

Year 1: Minimal Pruning

Limit pruning to removing damaged branches. Allow plants to focus energy on root establishment rather than replacement growth.

Year 2: Shaping Begins

Begin light shaping to encourage branching. For formal hedges, shear lightly to promote dense growth. Cut back any dominant leaders to encourage bushiness.

Year 3+: Regular Maintenance

Establish an annual pruning routine:

• Spring: Remove winter damage, shape before major growth begins
• Early summer: Light shearing for formal hedges
• Late summer (before August 1): Final shaping, allowing hardening before frost

Important: Never prune evergreens after mid-August in Northumberland County. New growth won't harden before winter and will suffer frost damage.

Formal vs. Informal Hedges

Formal Hedges

Require frequent shearing (2-3 times yearly) to maintain crisp lines. Prune so the base is slightly wider than the top—this "batter" ensures lower branches receive light and prevents bare legs at the base.

Informal Hedges

Need only occasional pruning to control size and remove dead wood. Choose naturally dense shrubs and allow their natural form to create a softer barrier.

Winter Protection

Young hedges in Northumberland County benefit from winter protection:

• Water deeply before ground freezes
• Apply anti-desiccant spray to evergreens in late fall
• Install burlap windbreaks on exposed sites (first 2-3 years)
• Protect from salt spray if near roads