|
|
| Geranium 'Rozanne' |
There are many varieties of hardy geranium that thrive in the Midwest. One of the longest blooming and most prolific blue-flowered cultivars has been selected as the Perennial Plant Association's 2008 Perennial Plant of the Year. Geranium ‘Rozanne’ is a patented sterile hybrid offering many great improvements over other cultivars (U. S. Plant Patent PP12175 issued October 30, 2001). It is hardy in zones 4 to 8.
The genus is native to Europe and Asia; this a natural hybrid of G. wallichianum ‘Buxton’s Variety’ and G. himalayense found in 1989 in the Somerset, England garden of Donald and Rozanne Waterer. In 2000 it was introduced by Blooms of Bressingham at the Chelsea flower show. This clump-forming variety has better heat tolerance, larger flowers and longer bloom than similar cultivars.
 |
| The flowers are purple to blue. |
The large (to 2½ inches diameter) saucer-shaped flowers are violet blue with purple-violet veins, small white centers and black anthers. In some light they appear almost iridescent with pink undertones, and in warmer weather tends more to the purple than blue. They are produced profusely in late spring and early summer. Unlike many other varieties, ‘Rozanne’ has great heat tolerance and flowering can continue for weeks or months, particularly when the summer is cool.
The plants grow in a mound about 18” tall and 24-36” wide, although younger plants tend to be low and spreading. The dark green leaves are generally round with 5 deeply cut lobes and appear slightly marbled. They turn reddish brown in fall.
 |
| 'Rozanne' is long blooming. |
Use geranium ‘Rozanne’ as individual specimen plants or in masses in the border. This cultivar looks at home in the rock garden and cottage garden as well. The blue flowers and attractive foliage combine well with a wide range of plants, and with its great weaving habit, ‘Rozanne’ fills in the gaps between plants perfectly. Try planting it in front of roses, as a groundcover, or as a filler between daylilies and taller perennials such as New England asters, purple coneflower, Siberian iris, garden phlox, or ornamental grasses. Combine with coreopsis for a nice purple and yellow combination with a long season of bloom. It makes a striking contrast in texture when combined with large-leaved hostas. ‘Rozanne’ is a good choice for interplanting with spring bulbs (to hide their yellowing foliage), and fall-bloooming bulbs such as Crocus speciosus or colchicums will look great poking through the foliage. It can also be used in larger patio planters, window boxes or hanging baskets.
Grow in full sun or partial shade. It does best in moist, organic soil but will tolerate drier conditions in soils ranging from normal to sandy to clay. Shear or trim to shape or control spread at any time. Cut back to 3-4” high after initial bloom to encourage additional bloom. It has no serious insect or disease problems and seldom needs dividing. Because it is a patented variety, self-propagation is prohibited at this time. A license is required for commercially propagation, which, like many of the new perennial varieties, is vegetatively produced by tissue culture.
–
Susan Mahr, University of Wisconsin - Madison 
You need Adobe Acrobat Reader version 5 or later to view or print this PDF. If
this software is not installed on your computer, you can
download a
free copy of Acrobat Reader.
