Geranium x oxonianum 'Diane's Treasure'
Hardy geraniums are 'good do-ers', reliably hardy perennials that will grow in most gardens, but have gained a reputation for seeding themselves around rather too vigorously. Geranium x oxonianum hybrids (a cross between G. endressii and Ger. versicolor) are common with over 60 listed in the RHS Plant Finder in 2019, so with plenty to choose from why add G. x ox. 'Diane's Treasure' to the Conservation Scheme? It was suggested as suitable for conservation last year and has not been listed in the Plant Finder since 2016.
This plant has been grown by HPS Hampshire Group for over 10 years and their original plant was a gift from the late Trevor Bath*, a geranium collector and expert, who found it to be an excellent plant with a long flowering period.
Ger. x ox. 'Diane's Treasure' was a chance seedling found by Diane Sutton in her garden in Southport and was registered by Annette Cutts of Bolton.
It forms a mound of mid-green foliage with reddish-purple star-shaped flowers. Plants should be cut back to ground level as flowering comes to an end to prevent seeding and to produce a fresh clump of foliage and often a second flush of flowers. It will grow in full sun or part-shade and can be propagated by division.
Plants will be grown by HPS members to see if it should be kept on the HPS conservation list.
*Trevor Bath ran Risetop Cottage Nursery in Mayford nr. Woking in Surrey and together with Joy Jones (a founder member of the HPS Hardy Geranium Group in 1974 and Chair for 20 years), co-authored The Gardener's Guide to Growing Hardy Geraniums' published in 1994. His name is linked to several other hardy geraniums including Ger. x ox. 'Trevor's White' which he spotted in his own garden. Perhaps the most well known is Ger. phaeum 'Lily Lovell', named after his mother, but he is also linked to Ger. phaeum 'Rose Madder' and Ger. phaeum 'Trevor's Recall'.