I bought a new hardy geranium last week. That is not news. Over the years I have developed a small collection of varieties that I love for their beautiful flowers, interesting leaves and adaptable dispositions. The sturdiest of my collection is Geranium macrorrhizum, the big-root geranium, with pink, five-petaled spring flowers and deeply dissected, apple-scented leaves that turn red in the fall. It is a wonderful ground cover that goes beautifully about its business no matter what else is going on.
Hardy geranium aficionados know that these plants are related to, but different from, the big-headed annual geraniums that many of us buy every spring to adorn our porches, patios, window boxes, and gardens. Both hardy geraniums and the common annual varieties belong to the vast geranium or Geraniaceae family. The tender annuals are known botanically as pelargoniums, but are commonly called “geraniums” or “zonal geraniums”. The hardy geraniums are perennials that can survive in cold winter climates. Some people call them ‘cranesbills” for the distinctive shape of their seed capsules.
The new geranium, ‘Azure Rush’, also has deeply dissected leaves, but they are smaller and more delicate than those of the big-leaf geranium. The foliage is lightly scented, and the bright blue, five-petaled flowers have a bit of lavender in their color profile. Each is about two inches wide and features a white or palest blue central “eye”. The petals are also strikingly veined in darker blue-purple.
When I first saw the blue-purple blooms of ‘Azure Rush’ on a nursery pallet, I thought I was looking at ‘Rozanne’, one of the current superstars of the horticultural world. Introduced in 2000 by renowned English nursery, Blooms of Bressingham, ‘Rozanne’ was the result of plant breeding done by an English couple named Waterer who crossed a European hardy geranium, Geranium wallichianum ‘Buxtons’, with an Asian hardy geranium, Geranium himalayense.. The resulting plant had lovely flowers and proved to be an all-around good grower, ambling through garden beds at about 18 inches tall, with a mature spread of about two feet. ‘Rozanne’ does not form solid, ground-covering mounds like some other hardy geraniums, but weaves itself in and out among other plants. The interweaving means that the blue-violet flowers offer lovely surprises wherever they pop up.
‘Rozanne’ had so many virtues—including alluring color, heat tolerance and repeat blooming–that plant merchandisers, botanical institutions and gardeners everywhere took notice. It was the Perennial Plant Association’s “Plant of the Year” in 2008, and the Royal Horticultural Society’s centennial “Plant of the Century” in 2013.
In the midst of all of that ‘Rozanne’ celebration, a German plantsman, Jan Dirk Schuiver, found a sport or spontaneous genetic mutation of ‘Rozanne’ in 2007. The sport had slightly lighter flowers, a more compact habit and a less sprawling disposition. The differences between the superstar parent plant and its genetic sport added up to a promising new introduction. Blooms of Bressingham introduced the sport, christened ‘Azure Rush’. This spring it is available from many plant merchandisers.
In a nutshell, ‘Azure Rush’ is similar to ‘Rozanne’, but boasts better manners and possibly, more flowers. Like its parent, it thrives in a variety of soils and prefers a sunny or lightly-shaded situation. It can grow nicely in containers, especially mixed container arrays.
For those of us with varmint issues, the cranesbills, including ‘Rozanne’ and ‘Azure Rush’, provide welcome respite from perpetual repellant spraying. Deer, rabbits and their predacious four-legged allies generally avoid them. The plants are easy to care for, though deadheading may increase flower production. Generally, ‘Azure Rush’ will flower on and off throughout the growing season. This makes a contrast from some other hardy geraniums that are “one and done” performers when it comes to seasonal flower production.
You may be able to find ‘Azure Rush’ at local nurseries and garden centers this spring. If not, you can buy both ‘Azure Rush’ and its parent, ‘Rozanne’, from Bluestone Perennials, 7211 Middle Ridge Rd., Madison, OH 44057; 800-852-5243; www.bluestoneperennials.com. Print catalog available.