The Perennial of the year for 2008 is Geranium ‘Rozanne’. This plant is a naturally occurring hybrid, a cross between Geranium himalayense and Geranium wallichianum ‘Buxton’s Variety’. It was introduced by Blooms of Bressingham. This is well regarded company based in the U.K. that that has, since the 1950’s, introduced over 200 perennial cultivars. Among them are plants that are very familiar to gardeners: Achillea ‘Moonshine’ and ‘Anthea’, Astilbe ‘Sprite’, Bergenia ‘Bressingham White’ and ‘Bressingham Ruby’, Crocosmia ‘Lucifer’, Dianthus ‘Oakington’, Geranium ‘Ann Folkard’, ‘Ballerina’ and ‘Rozanne’, Lavandula ‘Blue Cushion’, Leucanthemum ‘Snowcap’, and Phlox ‘Oakington Blue Eyes’, ‘Eva Cullum’ and ‘Franz Schubert’. Some of us grow Achillea ‘Moonshine’ and Crocosmia ‘Lucifer’ and possibly some of the others as well.
The company specializes in the selection and marketing of prize winning plants and many of its cultivars were developed by other growers. This particular cultivar comes from Somerset, England where two keen eyed gardeners Donald and Rozanne Waterer noticed that an accidental hybrid produced extraordinarily large flowers and bloomed continuously from June until November.
These are the two major qualities that set ‘Rozanne’ apart from the more common hardy blue geraniums such as ‘Johnson’s Blue’. The flowers reach 2 ½ inches across compared the 1 ½ inches of other geraniums. The plants begin blooming in late spring and bloom prolifically until frost. Commonly this type of geranium has a spurt of blooms in June and will bloom sporadically there after. Frequently, as the summer progresses the old foliage becomes leggy and must be cut back. This new cultivar has a mounding habit and spreads to a colossal 36 inches. Specimens have reached 4-5 feet.
The flower is a violet-blue with purple-red veining. The eye in the saucer shaped blossom is white. The foliage is deep green and slightly mottled with chartreuse; in the fall the leaves turn red.
Like our native Geranium maculatum or cranesbill ‘Rozanne’, prefers just a bit of shade and a rich, well drained soil. Extra humus in the soil will encourage spreading. ‘Rozanne is fairly drought tolerant after it has become established. Excess shade will result in fewer flowers and a less compact habit. The plant will not need to be divided for 3-4 years.
‘Rozanne’, at 20 inches in height, is recommended as a tall ground cover. It is especially attractive as a filler with daylilies, Siberian iris or phlox. The Perennial Plant Association suggest planting it with Shasta daisies Leucanthemum ‘Snowcap’) or Silver Princess. Veronica spicata ‘Tickled Pink’ is the society’s suggestion for a spectacular violet-pink combination.
Geranium ‘Rozanne’ is also good in baskets and planters where it will trail over the side of the containers. It may not survive the winter in a container since it is hardy from zone 5-8. For a surer over wintering it would be wise to at least heel the plant into the ground over the winter unless it can be kept in a protected area.
Geranium ‘Rozanne’ is available at Jung Seeds (http://www.jungseed.com/), Bluestone Perennials (www.bluestoneperennial.com) and at Wayside Gardens (http://www.waysidegardens.com/) prices range from $8.95-12.95.