Amethyst Hydrangea

Amethyst Hydrangea (Hydrangea macrophylla 'Amethyst') is a compact bigleaf hydrangea that reaches about 1m tall and 1m wide, small enough for a deck pot and substantial enough to anchor a border. Its large rounded flower heads open in soft pink and blue, and the exact shade follows your soil. It also handles a little more sun than most hydrangeas, which makes it an easier first plant.

Why you'll love it

• Colour that follows your soil. Alkaline or chalky soil pushes the heads towards pink, acid soil towards blue, and neutral soil gives lilac. A cheap pH test tells you which way yours will go.
• A size that fits small spaces. At about 1m by 1m it sits happily in a large pot on a balcony or deck as well as in a garden bed.
• More sun tolerant than most. It still wants relief from harsh afternoon heat, but it copes with more light than the shade-only types.
• Foliage with a seasonal shift. Soft light green leaves move towards antique copper tones as the year turns.
• Good for cutting and drying. The heads dry well, so a few stems from the plant make long-lasting indoor arrangements.

Where it works best

Pots, decks and balconies. Use a pot at least 40cm wide with quality potting mix and keep it moist.

Cottage and woodland-style borders. Plant 1m apart for a continuous border in rich soil, on the cooler side of the house or beneath open trees, with ferns and azaleas alongside.

Cut flower patch. Group three or four plants together and you have armfuls of stems to cut or dry each summer.

Growing Amethyst Hydrangea in Australia

Position and climate. Choose a partly shaded spot with morning sun and shade from the hot afternoon. Cool temperate gardens can give it more sun, while in subtropical gardens deep afternoon shade is essential. It is hardy when dormant, though a late frost can burn new spring growth.

Soil. Rich, moist, well-drained soil suits it. Dig in compost before planting and mulch about 5cm deep to keep the shallow roots cool. Keep the soil acid (around pH 5 or lower) for bluer heads, or neutral to alkaline for pinker ones.

Water and feed. Water regularly for the first 8 to 12 weeks until established, then give plenty of water in dry periods, since hydrangeas wilt fast when thirsty. Feed once with a slow release fertiliser as growth starts in spring.

Pruning. Bigleaf hydrangeas carry next summer's flowers on last year's stems, so never cut the whole plant back. Take faded flower heads off just above the next pair of leaves and cut out only dead or weak stems, or you will lose next summer's flowers.

What to expect when it arrives

We sell Amethyst Hydrangea as tube stock, in 140mm pots in packs of 10 and in 200mm pots in packs of 6. Tube stock is a young plant in an 80mm deep tube that establishes quickly, building roots and leaves first, so expect modest flowering in the first year and heavier heads from the second summer. The 200mm pots carry a bigger root system and give a faster display.

Plants are delivered Australia wide, with delivery from $29.95. Every plant is covered by our 30 day healthy plant guarantee.

Plant care guides and related reading

• Browse the full hydrangea range
• How hydrangea colour follows soil pH and when to prune
• More plants for partial shade
• Plants that grow well in pots

Common questions

Can I choose whether it flowers pink or blue?

To a degree. Acid soil gives bluer heads and neutral to alkaline soil gives pink, with lilac in between. Change the soil gradually and expect it to take a season or two to show.

Will it live in a pot all year?

Yes. Use a pot at least 40cm wide, water often and repot in late winter once the roots fill it. In summer, move it out of afternoon sun.

Is it safe for pets?

No. All parts of a hydrangea are toxic if eaten, to people and pets, so keep it away from chewing dogs and cats.