How to Prune Hydrangeas (Without Killing Them)

Hydrangeas are beautiful, dramatic, and wildly misunderstood.

Most pruning mistakes don’t happen because people are careless — they happen because hydrangeas all look similar but follow completely different rules.

This guide exists so you don’t have to guess.

If you remember one thing:

If you don’t know what type you have, don’t prune yet.

Let’s fix that.

Step 1: Identify Your Hydrangea (This Is the Whole Game)

Before touching pruners, identify what kind of hydrangea you have. Everything else depends on this.

Look at the FLOWERS first (fastest clue)

Big round balls (blue, pink, or purple)?

Bigleaf hydrangea

• Most common in home gardens

• Mophead or lacecap flowers

• Blooms on old wood

• Do not hard prune

Cone-shaped flowers (like ice-cream cones)?

Panicle hydrangea

• White → blush → pink

• Upright, sturdy

• Blooms on new wood

• Safe to prune hard

Big white snowballs (not cones, often floppy)?

Smooth hydrangea

• Usually ‘Annabelle’ types

• Blooms on new wood

• Safe to prune hard

Flat flowers with a ring of big petals?

Bigleaf (lacecap type)

• Still blooms on old wood

• Still dangerous to prune hard

Step 2: Check the LEAVES (Backup confirmation)

Oak-shaped leaves?

Oakleaf hydrangea

• Unmistakable leaf shape

• Beautiful fall color

• Blooms on old wood

• Minimal pruning only

Huge, soft, floppy leaves?

Bigleaf hydrangea

• Tender stems

• Most cold-sensitive

• Do not prune in spring

Smaller, firmer, pointy leaves?

Panicle hydrangea

• Shrubby, woody

• Looks tougher (because it is)

• Prune confidently

Step 3: Old Wood vs New Wood (The Rule That Saves Plants)

Old wood = last year’s stems

Cut them → you cut flowers.

Step 4: When to Prune (PNW-Friendly)

Late Winter / Early Spring (Feb–March)

Safe to prune:

• Panicle

• Smooth

Do NOT prune:

• Bigleaf

• Oakleaf

After Blooming (Summer)

• Deadhead spent flowers

• Light shaping only

• Stop by late summer

Fall

🚫 Don’t prune anything

Plants are setting buds and storing energy.

Step 5: How to Prune (Calm, Exact Instructions)

For NEW wood hydrangeas (Panicle & Smooth)

• Cut back to 12–24 inches

• Remove dead or crossing stems

• Aim for strong, open structure

You are not hurting it.

For OLD wood hydrangeas (Bigleaf & Oakleaf)

• Remove dead wood only

• Deadhead flowers by cutting just below the bloom

• Always cut above a healthy bud

When unsure → stop.

Step 6: “I Still Don’t Know What I Have” Emergency Guide

Answer honestly:

If you’re still unsure:

Do nothing this year.

That is always safer than guessing.

Common Hydrangea Crimes (You’re Forgiven)

• Pruning everything in March “to tidy it”

• Treating all hydrangeas the same

• Trusting random social media advice

• Assuming no flowers = plant failure

Hydrangeas are just dramatic communicators.

PNW Reality Check

In Zone 8:

• Winter damage can kill old wood

• Even “correct” pruning can fail after cold snaps

• Leaving plants alone is never wrong

Patience = flowers.

Final Odd Garden Rule

Blue or pink? Step away from the pruners.

White cones or snowballs? You’re safe.