How to prune hedge in first year: forming and basic structure

Why first-year pruning is critical

Many gardeners look at their new hedge and think: "Let it grow, I'll trim next year." This is a mistake. Year 1 determines everything. The pruning steps you take now define whether your hedge in 20 years is tight and compact, or wide and uneven.

A young hedge (newly planted, or 1 year old) grows wild. All energy goes up and sideways. Without pruning you get:

• Bare gaps at bottom (sparse-base effect)
• Irregular width (wider top)
• Poor interior density
• Difficult to fix later

With strategic first-year pruning you build a "skeleton" that carries forward for life.

First-year timing: when do you start?

This depends on planting timing:

Spring planted (March-April):

• Wait until June to start pruning (tree needs time to settle)
• June: first trim
• August: light trim
• Stop pruning after September (tree must build strength for winter)

Autumn planted (September-October):

• NO pruning in autumn/winter
• Wait until March next spring
• Then start first-year pruning

Summer planted (July-August):

• Very cautious in August only
• Prefer waiting until March next year

Golden rule: Prune young hedge minimally the first season. You want to stimulate growth, not slow it.

Step 1: inspection and goal setting

Before you start, decide: what shape do you want?

Rectangular profile (most formal):

• Vertical sides, flat top
• Requires more maintenance, very tight
• Work: annual trim needed

Trapezoid/tapered (wide bottom, narrow top):

• More light at bottom
• More rustic look
• Less intense maintenance
• RECOMMENDED for year 1

Triangle/pointed (peaked top):

• Water drains perfectly
• Classic look
• Much work to maintain point

For year 1: trapezoid shape is best choice. It gives you the most stable base and least work.

Step 2: determine desired dimensions

Measure and note:

• Desired final height: (e.g. 1.8 m, 2 m, 2.5 m)
• Desired width bottom: (e.g. 80 cm, 1 m, 1.2 m)
• Desired width top: (20-30 cm narrower than bottom)

This depends on your garden, neighbors, views. Fix this. You will work toward this over next years.

Example:

• Final height: 1.8 m (eye level)
• Width bottom: 1 m
• Width top: 40 cm (tapers upward)

Step 3: first pruning (June, year 1)

For thuja or mixed hedge (usually cautious):

1. Inspect sides: where does growth look strangest?
2. Gently trim drooping branches far from profile
3. Depth: only 2-3 cm (shallow!)
4. Top: let it grow, do not trim

This is mainly making space and correcting irregularities, not hard forming.

For thuja/Smaragd (columnar):

• Is your top already shaped well? Let it grow
• Sides gently trimmed, but not cut hard back
• Goal: only very protruding branches off

For Brabant or wider type:

• Sides can be trimmed more cautiously
• Width can grow, we mostly trim height and symmetry
• June: cautious, August can be slightly more

Step 4: August second touch (optional, fast-growing types only)

If your thuja or cypress grows very fast (30+ cm in two months):

1. Light side trim
2. Front check for symmetry
3. No hard pruning
4. Remove drooping branches
5. STOP after August, no September pruning

This gives your hedge more shape mid-season. Not mandatory.

Step 5: late-summer monitoring (September-October)

Look at your hedge:

• Growing evenly on both sides?
• Top still reasonable?
• Drooping branches?
• Gaps at bottom visible?

No pruning, but make notes. These are your takeaways for next March.

Preventing bottom gaps: critical rule

Many young hedges have bare bottoms by year 2. This is caused by:

1. Insufficient bottom-branch selection: You trim top only, bottom branches grow wild
2. Poor light at bottom: Not enough light reaches below - leaves drop
3. Back-to-front growth: Branches grow one layer dense behind another, no horizontal spread at bottom

Prevention in year 1:

• Ensure bottom 30 cm always stays wider than top
• Never cut sides vertically; always angled (wider below)
• Let bottom branches grow more than top branches
• Ensure trapezoid shape

This is the secret of full hedges from bottom to top.

Thuja vs. Leyland cypress: form difference year 1

Thuja (Smaragd, Brabant):

• Grows more vertical, less sideways
• Can be cut more cautiously
• Trapezoid shape requires more side trimming
• August trim is OK

Leyland cypress:

• Grows aggressively sideways
• Very shallow trimming (3-5 mm only)
• Trapezoid shape forms faster naturally (you do less)
• NO August trim, June only

Juniper (juniperus):

• Slow grower
• Minimal first-year pruning
• Let almost everything grow, shape follows
• Second-year forming better

First-year frequently asked questions

My hedge grows lopsided - one side wider. What now?

This is normal. Side may get more sun, or variation in soil quality. Trim the wider side slightly more (1-2 cm deeper). Next year it will even out.

Can I prune my hedge in May?

Better not. Too early in season. June is safer - tree has built more strength. May pruning can slow growth.

Must I make my hedge neat for guests? It looks untidy in June.

No. Year 1 can look messy. This is investment phase. Neat hedges are year 3+ work. Be patient.

My hedge looks thinner after June pruning. Is that normal?

Yes. You removed volume. It looks thinner, but it regrows fast. June-July-August: heavy growth. Early September: full again.

How young is "young" really? When does first-year phase end?

Usually:

• Year 1: foundational forming
• Year 2: further refinement
• Year 3+: maintenance phase (annual trim)

But a small hedge plant can be year 1-2, a large one maybe only first few months. Use: height determines. < 1 m tall = mainly first-year phase.

My hedge is already 1.5 m when planted. Is this still first year?

Yes. Regardless of size: first 12 months after planting = year 1 forming. Same rules apply.

Step-by-step first-year hedge forming

Step 1: Plan shape and dimensions

Choose trapezoid. Note: final height, width bottom, width top.

Step 2: Inspection (June)

Look at growth. Symmetry? Drooping branches?

Step 3: First pruning (June, minimal)

Sides carefully; drooping branches off. 2-3 cm depth max. Let top grow.

Step 4: August check (optional)

Fast-growing hedges: light trim. Others: wait.

Step 5: September-October monitoring

No pruning. Take notes for next March.

Step 6: October-December growth

Let growth continue. Tree builds energy reserves for winter.

Cultivar preferences

Thuja Smaragd:

• Very upright. Trapezoid shape requires attention.
• Year 1: very shallow trimming.

Thuja Brabant:

• Naturally wider. Trapezoid forms more easily.
• Year 1: sides can be cut more (cautiously).

Leyland cypress:

• Grows wild, lots of sideways.
• Year 1: very cautious, only drooping branches.
• NO August pruning.

Boxwood/Yew (fine woodwork):

• Slow. Year 1: minimal pruning.
• Forming starts year 2.

Privet:

• Fast-growing. Year 1: can be cut more.
• Trapezoid requires attention but forms fast.

Conclusion: patience wins

First-year hedge forming is patience. You do little, you wait much. This goes against instinct (you want immediate neat shape). But this patience pays off: by year 3-5 you have a hedge that is tight, full and healthy without constant work.

The foundation built in year 1 determines decades. Do it right now, and your hedge thanks you later.

Discover your garden design

At gardenworld.app you can upload your front yard and see how your young hedge grows into it. Plan your hedge shape, see plant combinations, and visualise your front yard's future.

First-year pruning: minimal work, maximum impact.