Purple Hydrangea: A Complete Guide

A purple hydrangea brings rich, elegant colour to the garden, sitting beautifully between classic blue and pink shades. Purple blooms are especially popular in borders and containers and are often influenced by soil conditions, making them a fascinating and flexible choice for UK gardeners.

⭐ Recommended Products — Hydrangeas & Pruning Essentials

Hydrangeas are show-stopping shrubs that bloom beautifully when properly cared for and pruned at the right time.

• Hydrangea Pruning Shears (Bypass Secateurs)
Sharp, precision pruning shears that make clean cuts on hydrangea stems without crushing them — perfect for regular shaping and deadheading.
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• Ergonomic Loppers for Thicker Stems
Useful for cutting back larger, older stems on big hydrangea bushes — comfortable handles help reduce strain.
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• Protective Gardening Gloves (Pruning & Shrub Work)
Durable gloves that protect your hands while pruning, handling branches, or working around woody stems.
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• Hydrangea Fertiliser & Feed
A balanced plant food to support strong growth and vibrant blooms — apply in spring and mid-summer for best results.
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• Hydrangea Care & Pruning Guide Book
A handy reference that covers pruning times, techniques for different hydrangea types (mophead, lacecap, paniculata), and season-by-season upkeep.
👉 Click here to see top options

This guide explains what makes hydrangeas turn purple, which types produce purple flowers, and how to care for them properly.

🌸 What Is a Purple Hydrangea?

Purple hydrangeas are usually mophead or lacecap hydrangeas (Hydrangea macrophylla) whose flower colour falls between blue and pink. The purple shade appears when soil pH is slightly acidic to neutral.

Some varieties naturally lean purple, while others change colour depending on soil chemistry.

🌱 Which Hydrangeas Can Be Purple?

Purple flowers are most commonly seen on:

• Mophead hydrangeas – large, rounded flower heads
• Lacecap hydrangeas – flat flowers with delicate outer petals

Panicle and smooth hydrangeas do not change colour and will not turn purple.

🌿 Why Hydrangeas Turn Purple

Hydrangea flower colour depends on soil pH and aluminium availability:

• Acidic soil → blue flowers
• Neutral soil → purple flowers
• Alkaline soil → pink flowers

Purple is essentially the transition colour between blue and pink.

To encourage purple blooms:

• Avoid adding lime to the soil
• Do not use strong ericaceous feeds
• Maintain balanced, organic-rich soil

🌞 Best Position for Purple Hydrangeas

Purple hydrangeas grow best in:

• Partial shade or morning sun
• Sheltered positions
• Moist but well-drained soil

Strong afternoon sun can fade colour and scorch leaves.

🌿 Soil Requirements

For the best purple colour, soil should be:

• Moist but free draining
• Rich in organic matter
• Slightly acidic to neutral

Mulching annually with compost or leaf mould helps stabilise soil pH and moisture.

✂️ Pruning Purple Hydrangeas

Most purple hydrangeas flower on old wood.

When to prune:

• Late winter to early spring

How to prune:

• Remove dead flower heads only
• Cut back to the first healthy pair of buds
• Remove dead or weak stems at the base
• Avoid hard pruning

Over-pruning is a common reason for poor flowering.

💧 Watering and Feeding

For healthy plants and good colour:

• Water regularly during dry spells
• Keep soil evenly moist
• Feed lightly in spring with a balanced fertiliser
• Avoid excessive feeding, which encourages leaf growth over flowers

Container-grown plants need more frequent watering.

🌼 Using Purple Hydrangeas in the Garden

Purple hydrangeas are ideal for:

• Mixed borders
• Patio containers
• Cottage-style gardens
• Shaded or woodland planting schemes

They pair particularly well with white flowers, silver foliage, and deep green plants.

🌸 Final Thoughts

Purple hydrangeas offer depth, elegance, and flexibility in the garden. With the right soil conditions, gentle pruning, and consistent moisture, they will reward you with stunning colour year after year.

If you want a hydrangea that stands out without being overpowering, purple hydrangeas are an excellent choice.