Girl and boy coloured hydrangea by the bay at Trebah Garden, Cornwall

Thanks to Ray Townsend (Woody Collections and Sward Manager at Kew, Trustee of Trebah Garden and no slouch with bamboos) and Darren Dickey (Head Gardener at Trebah Garden), Lynda and I had an expertly guided tour of Trebah Garden yesterday.

Trebah Garden is in the far west corner of Cornwall, half an hour or so by hedge-row lined roads from Falmouth (i.e. a couple of miles). 'Trebah' means house by the bay and indeed the family home looks over the garden down to a gorgeous bay.

Charles Fox created the garden in 1838, at this location first mentioned in the Doomsday Book. Since then (1838 rather than 1086) the property changed hands a number of times until Tony and Eira Hibbert bought it in 1981, opening it to the public in 1987. In 1990 the house and garden were transferred to the Trebah Garden Trust who have added a visitor centre and a very fine cafe. 

The setting - a deep protected valley down to a sheltered beach - and the collection of hundred-year-old rhododendrons, camellias and magnolias, plus a smattering of plants from warmer climes, make Trebah Garden quite different to other grand gardens in England.

The signature plants for many visitors though are the hydrangeas and giant gunneras filling the lower valley. Gunnera manicata has a bad name these days as a weed in Cornwall (and elsewhere) but here in Trebah Gardens it reaches such spectacular size and extent it's hard not to be impressed, and to forgive its virulence.

I'm not aware of Hydrangea macrophylla having any invasive tendencies but it certainly flourishes beside the stream here in Trebah Gardens, at least while the gunnera is kept under control upstream. 

Given my persuasive argument about the colour of Big-leaf Hydrangea flowers depending on the amount of aluminium in the soil, and usually linked to acidity, how do they get pink and blue flowered plants growing next to each other? 

I got two different answers from our guides: either the pink flowered individuals were grown in specially prepared compost (and they will convert to blue as they settle into their garden position) or there are genetic strains that remain pink or blue no matter what the soil chemistry. I prefer the first answer but will need to visit again in a few years and check out the distribution of colours in this picture (assuming Darren doesn't replace them first...).

If Ray has his way Trebah Garden will also be known for its bamboos. It has plenty of different species (39), and a fledgling 'bamboozle' (a maze of paths through bamboos), but Darren and Ray want to lift the bamboo experience to another level with clever plantings and improved presentation. You can already see bamboos (Phyllostachys edulis) with thicker canes here than anywhere else in the UK.

And there is plenty more, such as this Giverny inspired bridge and one gunnera that won't invade Cornwall.

Images: They don't do the garden justice!

Postscript 30 July 2012: Featured on the Highgrove Gardens website
Hydrangea macrophylla 'Pia'"Hydrangea macrophylla ‘Pia’ ...has a dwarf habit growing to 70cm in height and spread, keeping a good bright pink flower colour no matter what the soil type." The forms at Trebah were not dwarf, but this does support the alternative explanation, where some varieties do flower pink no matter what!