Admirable Avens - the Genus Geum
(Editor's Note: This article was originally published on May 2, 2009. Your comments are welcome, but please be aware that authors of previously published articles may not be able to respond to your questions.)
It is a well known fact that different regions have different common names for a given plant. Let's take Geum as an example. The genus Geum is most commonly called avens. Geum triflorum, a species from the grasslands of North America, goes by the common name of prairie smoke, old man's whiskers, grandfather's-beard, lion's-beard and purple avens. Geum rivale is known as water avens, chocolate root, Indian chocolate and also purple avens. Growing up, a common garden plant in my area was Geum ‘Werner Arends' (aka ‘Borisii'). I never knew it as an avens, rather we called it wild geranium. I guess the only orange flower common in my area in the 1960-70's were florist geraniums, so that name was loaned to this orange-flowered avens.
Let's look at Geum a little closer. Geum are members of the rose family. There are about 50 species found worldwide, primarily in temperate or montane regions. From thick rhizomes, plants form clumps of low-held, mostly evergreen leaves and taller wiry stems topped with a single or loose cluster of mostly 5-petalled flowers. Flower colour ranges from white through yellow, orange and red. Spring to early summer is the normal blooming season although some of the larger hybrids can bloom off and on all season. All have seeds with plumes of some sort, lending some to have very attractive seedheads. Plant heights vary from a few inches to nearly 3 feet.
In the wild, plants grow in two main habitats; woodlands or alpine meadows. The former plants are generally taller and multi-flowering while the latter are low with either solitary or small clusters of flowers. Woodland types prefer a moist, highly organic soil. While dappled shade is best, they will withstand full sun if the soil remains moderately moist. The alpine types require well-drained soil and full sun and are best used in the rock garden. With the possible exception of G. triflorum, Geum prefer soil that is slightly acidic. Most are hardy to zone 4.
The most ornamental species are G. chiloense (from Chile) and G. coccineum (from the Balkans) and hybrids between them. These are the tallest avens with flower stems held well above the foliage. Their long stems and somewhat clustered flowers make them suitable as cut-flowers. Many of the named cultivars have double flowers, adding to their attraction. There are many named cultivars with ‘Mrs. Bradshaw' (double red), ‘Lady Strathedon' (double yellow) and ‘Werner Arends' (aka ‘Borisii'; semi-double orange) being the most popular. Others to look for include ‘Blazing Sunset' (bright scarlet),' Fireball' (orange), ‘Mango Lassi' (yellow with orange margin), ‘Paso Doble' (scarlet), ‘Red Dragon' (red), ‘Bell Bank' (pink) and ‘Fire Opal'(orange-scarlet).
Some popular cultivars of avens include 'Mrs. Bradshaw', 'Lady Strathedon', 'Mango Lassi', 'Paso Doble' (top row) 'Red Dragon', 'Fire Glow' and 'Werner Arends' (bottom row)
The other woodland species that is reasonably popular is the water avens, G. rivale. This species occurs both in Europe and North America but the populations differ quite a bit. Both have nodding peach-apricot flowers but American populations form large plants with small flowers while European plants are more compact with much larger flowers. There are several named cultivars of the European G. rivale including ‘Album' (white), ‘Leonardii' (copper-pink) and ‘Lionel Cox' (yellow tinted pink).
Geum rivale and the cultivar 'Leonardii'; the last pic is 'Lemon Drop', a hybrid between G. rivale and G. montanum
There are a host of woodland avens with rather small unassuming flowers. These are suitable subjects for the woodland or wildflower garden. These include G. aleppicum (temperate Northern hemisphere, yellow), G. macrophyllum (North America, yellow), G. canadense (North America, white) and G. urbanum (Europe, yellow).
Suitable species for the wildflower/shade garden include G. canadense, G. aleppicum and G. macrophyllum
There are several attractive alpine or sub-alpine species which are small enough to use in the rock garden. Geum triflorum (North America) has nodding maroon to yellow-pink flowers usually in clusters of three. After they bloom, plants produce very attractive feathery seedheads not unlike those of mountain avens (Dryas) or a miniature pasque-flower (Pulsatilla). From alpine regions of Europe comes G. montanum. This species has reasonably large upward-facing yellow flowers. A lovely dwarf hybrid between G. rivale and G. montanum is ‘Lemon Drop' which had nodding yellow flowers not unlike a large-flowered G. rivale. From the Appalachians comes another semi-dwarf species called G. radiatum. This one also has yellow flowers. The two most choice alpine avens are the European G. reptans and the North American G. rossii. The former has large yellow flowers that arise from deeply divided, almost fern-like leaves. Plants spread via stolons similar to a strawberry. Overall, this avens gives the impression of being more like a low, creeping potentilla. The seeds produce quite attractive plumes not unlike G. triflorum. Geum rossii has the finest, most dainty and shiny foliage of any avens. They are also one of the few deciduous species. Like G. reptans, their flowers are yellow and reasonably large. These two are a little more challenging to grow in the garden as they dislike summer heat.
Alpine species from Europe include G. reptans and G. montanum
Alpine species from North America include G. radiatum, G. rossii and G. triflorum
If you currently do not grow any Geum in your garden, give them a second look. Their natural diversity makes them admirable additions to the garden, whether in a perennial border, woodland setting, wildflower garden or alpine gardens.
I would like to thank the following people for the use of their pictures: claypa (G. canadense), echoes ('Paso Doble'), EstelleMirage ('Lady Strathedon'), Galanthophile ('Lemon Drops'), GardenGuyKin ('Mango Lassi'), JamesCO ('Red Dragon'), mrporl ('Mrs. Bradshaw'), Terri1948 (G. rivale 'Leonardii'), Tigernach (G. radiatum), wildgingerfarm (G. reptans) and willmetge ('Fire Opal')