Hydrangea Care Guide for BC 

How to Plant, Prune & Grow Hydrangeas Successfully 

Hydrangeas are among the most versatile flowering shrubs for BC gardens, offering dramatic blooms from summer through fall. However, different hydrangea types have different pruning and care requirements — understanding your variety is the key to success. 

With proper placement and pruning, hydrangeas are long-lived, reliable performers across much of British Columbia. 

 

Understanding Hydrangea Types 

Mophead & Lacecap (Hydrangea macrophylla) 

• Rounded or flattened flower heads 

• Pink, blue, or purple blooms (colour influenced by soil pH – see our colour changing section below for more details) 

• Bloom on old wood (last year’s growth) 

Smooth Hydrangea (Hydrangea arborescens) 

• Very large white or pink ball-shaped flowers 

• Very hardy 

• Bloom on new wood 

Panicle Hydrangea (Hydrangea paniculata) 

• Cone-shaped flower clusters 

• White aging to pink 

• Very hardy and sun tolerant 

• Bloom on new wood 

Oakleaf Hydrangea (Hydrangea quercifolia) 

• Large cone flowers 

• Distinct oak-shaped leaves 

• Excellent fall colour 

• Bloom on old wood 

Climbing Hydrangea (Hydrangea anomala petiolaris) 

• Clinging vine 

• Lacecap-style white blooms 

• Excellent for shade walls and fences 

Visit your local GARDENWORKS to confirm your hydrangea type before pruning. 

 

How to Plant Hydrangeas 

Sun Requirements 

• Mophead & Oakleaf: Morning sun, afternoon shade 

• Smooth: Sun to part shade 

• Panicle: Full sun to part shade 

• Climbing: Part shade to shade 

Inland gardens require more afternoon protection. 

 

Soil Requirements 

• Rich, well-drained soil 

• High organic matter 

• Consistent moisture 

For blue Mophead hydrangeas: 

• Acidic soil encourages blue flowers 

• Alkaline soil produces pink flowers 

 

Planting Steps 

1. Dig a hole twice as wide as the root ball. 

2. Amend soil with compost. 

3. Plant at the same depth as in container. 

4. Water deeply. 

5. Apply 2–3 inches of mulch. 

 

Watering Hydrangeas 

Hydrangeas need consistent moisture. 

• Water deeply during dry spells 

• Avoid allowing soil to dry completely 

• Mulch annually to retain moisture 

• Climbing hydrangeas need regular moisture while establishing 

Panicle hydrangeas tolerate more drought than Mopheads. 

 

Fertilizing Hydrangeas 

• Apply compost in early spring 

• Use balanced slow-release fertilizer if needed 

• Avoid over-fertilizing 

Too much nitrogen reduces bloom production. 

 

Pruning Hydrangeas (By Type) 

Pruning depends entirely on the type. 

Mophead & Oakleaf (Bloom on Old Wood) 

• Do NOT prune heavily in spring 

• Remove only dead stems in early spring 

• Shape lightly immediately after flowering 

Smooth Hydrangea (Bloom on New Wood) 

• Cut back to 12–18 inches in late winter or early spring 

• Encourages strong new flowering stems 

Panicle Hydrangea (Bloom on New Wood) 

• Prune in late winter or early spring 

• Can be cut back by 1/3 to shape 

Climbing Hydrangea 

• Minimal pruning required 

• Light shaping after flowering 

Improper pruning is the most common reason hydrangeas fail to bloom. 

Hydrangea Type	Blooms On	When to Prune	How Much to Prune	Notes
Mophead (Macrophylla)	Old wood	After flowering (summer)	Light shaping only	Avoid spring pruning or you’ll remove flower buds
Oakleaf	Old wood	After flowering	Minimal pruning	Remove dead wood in early spring
Smooth (Arborescens)	New wood	Late winter / early spring	Cut back to 12–18 inches	Encourages strong new stems
Panicle	New wood	Late winter / early spring	Reduce by up to 1/3	Very forgiving and beginner-friendly
Climbing	Old wood	After flowering	Light shaping	Rarely needs pruning

 

Simple Rule to Remember 

If it blooms on old wood, prune after flowering. 
If it blooms on new wood, prune in late winter or early spring. 

Improper pruning is the #1 reason hydrangeas fail to bloom. 

 

Hydrangea Colour Change Guide (Mophead Varieties) 

Only Mophead (Hydrangea macrophylla) varieties change colour based on soil chemistry. 

 

Why Do Hydrangeas Change Colour? 

Flower colour is influenced by soil pH: 

• Acidic soil (lower pH) → Blue flowers 

• Neutral soil → Purple tones 

• Alkaline soil (higher pH) → Pink flowers 

The colour change happens because soil pH affects aluminum availability in the soil. 

 

 

Growing Blue Hydrangeas 

To encourage blue blooms: 

• Maintain acidic soil (pH 5.2–5.5) 

• Apply soil acidifiers as directed. We recommend Organique Soil Acidifier  

• Use fertilizers formulated for acid-loving plants 

Coastal BC soils are often naturally more acidic, making blue blooms easier to achieve. 

 

Growing Pink Hydrangeas 

To encourage pink blooms: 

• Maintain neutral to slightly alkaline soil 

• Avoid soil acidifiers 

• Lime should be added several times a year if soil is very acidic 

In Penticton and the Okanagan, naturally alkaline soils often produce pink flowers more easily. 

 

Important Notes 

• White hydrangeas do not change colour 

• Panicle and Smooth hydrangeas do not change colour other than getting a pink tinge as the weather cools in the fall. 

• Colour adjustment takes time — often a full growing season.  Dolomite Lime or soil acidifier must be applied every season.   

 

 

Growing Hydrangeas in South Coastal BC 

Hydrangeas perform exceptionally well in coastal BC. 

Climate Advantages 

• Mild winters 

• Moderate summer heat 

• Higher humidity 

Mophead and Oakleaf hydrangeas thrive in coastal conditions. 

 

 

Coastal Considerations 

• Ensure good drainage in clay soils 

• Provide afternoon shade for Mopheads 

• Winter protection rarely needed 

 

Growing Hydrangeas in Penticton & the Okanagan 

Hydrangeas can grow inland, but variety selection is important. 

Climate Challenges 

• Hot, dry summers 

• Colder winter lows 

• Lower humidity 

 

Best Types for Penticton 

• Panicle hydrangeas (most reliable) 

• Smooth hydrangeas 

• Oakleaf in protected shade 

Mophead hydrangeas may struggle with winter dieback inland. 

 

Inland Care Adjustments 

• Provide afternoon shade 

• Water consistently 

• Mulch heavily 

• Protect from winter wind exposure 

 

Companion Plants for Hydrangeas 

Hydrangeas pair beautifully with layered plantings. 

Shrubs 

• Rhododendrons (coastal areas) 

• Lily of the Valley Shrub (Pieris) 

• Ninebark 

Perennials 

• Hostas 

• Ferns 

• Heuchera 

• Hellebores 

Ground Layer 

• Epimedium 

• Tiarella (Foamflower) 

• Wild ginger (Asarum caudatum) 

 

Seasonal Hydrangea Care Calendar 

Early Spring 

• Prune new-wood types such as smooth and panicle varieties 

• Compost top-dress  

Late Spring 

• Light shaping of old-wood types 

Summer 

• Deep watering 

• Monitor heat stress inland 

Fall 

• Avoid heavy pruning 

• Maintain mulch 

Winter 

• Protect Mopheads inland 

 

Hydrangea FAQs 

Why isn’t my hydrangea blooming? 
Incorrect pruning timing is the most common cause. 

Can hydrangeas grow in Penticton? 
Yes, especially panicle and smooth hydrangeas. 

How do I make hydrangeas blue? 
Acidic soil encourages blue blooms in Mophead varieties. 

When should I prune hydrangeas in BC? 
It depends on the type — confirm whether it blooms on old or new wood.