There are about 300 species of geraniums. There is even a species of Geranium (Geranium maculatum) that is native to Iowa woodlands. Perennial or hardy geraniums are the “true geraniums” -- unlike the common “annual geraniums” (genus Pelargonium), which are often grown in outdoor containers. Perennial geraniums are also called cranesbills because their long, slender fruit resemble the beak or bill of a crane.
Cranesbills are an underutilized species of perennials in Iowa landscapes. Cranesbills are reliable bloomers in sites in full sun to part shade with well-drained soils. They have few insect or disease problems, and are often long-lived in the landscape.
There are many species and cultivars available to gardeners. In fact, the sheer number of cultivars available is daunting. Perennial geraniums vary in bloom time, flower color, flower size, height, leaf color, and habit. Depending on species/cultivar, most flower for 2 to 4 weeks, beginning in mid to late spring and finishing sometime in summer. Flower colors range from pale pinks, lavender, and white to intense purple-pink, maroon, or blues with dark or light contrasting centers or veining. Leaves are lobed or somewhat dissected. Most have medium green leaves, but a few species like G. pheaum or G. pratense cultivars have dark purple leaves or dark markings on leaves in spring. Several cranesbill species develop red or burgundy leaf color in fall. Some species sprawl, while others have a more mounding habit. Finding one that suits your landscape is fairly easy. Because there are so many species and cultivars available to the public, the Chicago Botanic Garden has evaluated many of them for their performance in the garden. The table below is information compiled from their published trials of the better performers for Midwestern landscapes.
Visit https://www.chicagobotanic.org/sites/default/files/pdf/plantinfo/geraniumfinegardening2012.pdf for more detailed comparison of cultivars.
|
Species and Cultivar |
Height (inches) |
Width (inches) |
Flower color |
Bloom time |
|
Geranium ‘Ann Folkard’ |
18 |
36 |
Purple-pink w/dark eye |
Spring-mid summer |
|
G. ‘Blue Cloud’ |
26 |
40 |
Lavender-blue |
Spring-mid summer |
|
G. ‘Brookside’ |
24 |
38 |
Lavender-blue |
Spring-late summer |
|
G. x cantabrigiense ‘Biokovo’ |
9 |
20 |
White w/pink |
Spring-early summer |
|
G. x cantabrigiense ‘Cambridge’ |
9 |
21 |
Deep pink |
Spring
|
|
G. x cantabrigiense ‘St. Ola’ |
10 |
43 |
White |
Spring-early summer |
|
G. himlayense ‘Gravetye’ |
15 |
30 |
Blue |
Spring-early summer |
|
G. ibericum ‘Rosemoor’ |
12 |
18 |
Violet-blue |
Spring-early summer |
|
G. ‘Johnson’s Blue’ |
24 |
33 |
Blue |
Spring-early summer |
|
G. macrorrhizum ‘Ingwersen’s Variety’ |
14 |
42 |
Light pink |
Spring |
|
G. macrorrhizum ‘Lohfelden’ |
8 |
18 |
Pale pink |
Spring-early summer |
|
G. maculatum ‘Elizabeth Ann’ |
22 |
30 |
Lavender-pink |
Spring-early summer |
|
G. maculatum ‘Espresso’ |
18 |
27 |
Lavender-pink |
Spring-early summer |
|
G. ‘Moran’ |
24 |
26 |
Violet-blue |
Spring
|
|
G. ‘Orion’ |
30 |
72 |
Purple-blue |
Spring-late summer |
|
G. ‘Perfect Storm’ |
8 |
24 |
Magenta-pink w/dark eye |
Spring-late fall |
|
G. phaeum ‘Margaret Wilson’ |
13 |
27 |
Purple w/white eye |
Spring |
|
G. playpetalum |
16 |
25 |
Violet-blue |
Spring-early summer |
|
G. pratense ‘New Dimension’ |
11 |
33 |
Lavender-blue |
Spring-mid summer |
|
G. pratense Victor Reiter |
14 |
21 |
Purple-blue |
Spring-mid summer |
|
G. Rozanne (‘Gerwat’) |
20 |
60 |
Purple-blue |
Early summer-fall |
|
G. sanguineum ‘Elsbeth’ |
20 |
32 |
Magenta |
Spring-mid summer |
|
G. sanguineum ‘Rod Leeds’ |
20 |
60 |
Magenta |
Spring-mid summer |
|
G. soboliferum ‘Butterfly Kisses’ |
20 |
50 |
Purple-pink w/red veins |
Late summer-fall |
|
G. soboliferum ‘Starman’ |
16 |
36 |
Purple w/dark centers |
Late summer-fall |
|
G. ‘Sweet Heidy’ |
20 |
72 |
Purple w/pale eye |
Spring-late fall |
|
G. ‘Tiny Monster’ |
18 |
54 |
Magenta |
Spring-late fall |
|
G. wallichianum ‘Buxton’s Variety’ |
16 |
48 |
Purple-blue |
Spring-late fall |
Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Horticulture and Home Pest News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on May 24, 2019. The information contained within may not be the most current and accurate depending on when it is accessed.