Wandering through the garden to check for any damage caused by a very windy, wet August night I saw that one of the Californian lilacs was already in full bloom. Ceanothus arboreus ‘Trewithen Blue’ makes an evergreen small tree growing, with us, up to 5 metres tall. Its 12cm long, fragrant, powder blue flower panicles are displayed from August until early October.
Belying the reputation of the genus for being short lived one of our ‘Trewithen Blue’ trees is more than 25 years old. Ceanothus like dry summers and are likely to be killed by over watering. We have some Ceanothus plants growing on a hot dry bank that haven’t been watered for 20 years or more which are still going strong.
Ceanothus arboreus is known in California as the Island Ceanothus as it only grows wild on one Mexican and three Californian islands where it inhabits chapparal, woodlands and pine forests on rocky slopes and exposed ridges.
Several selections of C. arboreus are grown in California but as far as I know only ‘Trewithen Blue’ is grown in Australia. It was raised by George Johnstone, who owned the Trewithen estate in Cornwell during the early 20th century. I first saw it growing in one of the lawns of the 20 acre Pirianda Gardens in the Dandenongs when the garden owners and builders the late Mr and Mrs Harvey Ansell were still alive. On their death they left the gardens to the people of Victoria. Mr Ansell died first and for a year or so on fine Sunday mornings I would pick a rather frail Mrs Ansell up from her house in the middle of the property and drive her around the garden so that she could inspect her trees.
During the 1950s, 60s and 70s the Ansells imported many fine trees from Hillier’s Nursery in the UK. Many of these trees are now reaching maturity. The garden is open to the public every day of the year except Christmas Day is well worth a visit.