Hamburg Hydrangea

Hamburg Hydrangea (Hydrangea macrophylla 'Hamburg') is a deciduous shrub about 1.2m tall and wide, with large, rounded flower heads that are usually purple. They shift to deeper blue-purple in acid soil and rose pink in neutral to alkaline soil, so you get some say in the colour. It is very cold hardy and carries soft light green leaves.

Why you'll love it

• Colour you can steer. Soil with a pH of 5 or lower gives blue flowers, while neutral to alkaline soil (pH 6 to 7) gives mauve, pink or even red.
• Very cold hardy. It shrugs off cold winters, so it suits the coldest gardens that hydrangeas can grow in.
• Big, rounded heads. The flower heads are large and full, and the leaves are soft and light green.
• Fits many roles. It works in cottage gardens, woodland style beds, mixed borders and large containers.

Where it works best

Mixed beds and cottage borders. Plant 1m apart. At 1.2m wide the shrubs overlap just enough to make a continuous flowering mass.

Woodland planting. Under high tree canopy, where the light is dappled and the soil stays moist, it grows with little fuss.

Large containers. A big pot with good drainage suits it. Water often, and keep it out of hot afternoon sun.

Growing Hamburg Hydrangea in Australia

Position and climate. Part shade suits it, and Hamburg is at its best in cool temperate and warm temperate gardens. In subtropical gardens give it deep afternoon shade. Protect it from harsh sunlight.

Soil. Rich soil with plenty of organic matter that stays moist without waterlogging. Adjust the pH if you want a particular colour, and mulch the roots.

Water and feed. Keep the water up through the first two to three months while it settles, and give plenty of water in dry periods. Apply a slow release fertiliser in early spring.

Pruning. It flowers on old wood, so give it space and avoid hard cutting. Trim faded flower heads back to a pair of healthy leaves. All parts of the plant are toxic if eaten.

What to expect when it arrives

We sell Hamburg 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. The 140mm and 200mm pots give a bigger plant on day one for a border or a pot. Expect flowering to build over the first couple of seasons.

The tube comes from our grower and is not always in stock. When the grower has none, it shows as sold out, and the notify button on the page emails you the day it is back.

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

• Our full hydrangea range
• Hydrangea colour and pruning guide
• Plants for cool climates
• More frost hardy plants

Common questions

How do I get blue flowers?

Grow it in acid soil, with a pH near 5 or lower. A neutral to alkaline pH of 6 to 7 gives mauve, pink or red, so test your soil before planting.

Will it cope with frost?

Yes. It is very cold hardy. Like all macrophylla hydrangeas it drops its leaves in winter, and a late frost can nip soft new growth.

Is it safe for pets?

No. Hydrangeas are toxic to dogs and cats if eaten, so grow it where pets cannot chew the leaves or flowers.