Who else was raised thinking geraniums were red, white, pink or orange, usually found in hanging pots or in window boxes? That was my understanding, until I was schooled at the nurseries where I worked later in life. The bright-colored flowers I knew as geraniums were actually Pelargoniums. Still in the same family, "geranium" is their common name. Whereas Geranium is a particular genus that our 'Johnson's Blue' belongs. Purples, pinks, and white are available from other species, but G. 'Johnson Blue' is the bluest (although it still has a bit of purple in the coloring). What do you think? Is it blue or purple? Maybe the best way to answer is to look in person rather than the photos available on the internet.
Like other Geraniums, 'Johnson's Blue' is a billowy mound of leaves with its flower stems rising slightly above. The flower stalks can become a little floppy under the weight of the flowers, especially when wet. They should bounce back after drying. A worthwhile addition to perennial borders, Johnson's Blue cranesbill, if you want to give it a common name, is hardy despite its delicate appeal. As with most Geraniums, they can also be added as an understory to larger plants. The Royal Horticulture Society recommends planting them under roses or other shrubs, but of course it all depends on which ones allowing plants and blooms under their limbs.
Botanical Name: Gerainum 'Johnson's Blue'
Geranium: Greek, geranos for crane. The fruit looks like a crane's bill.
Common Name: Johnson's blue cranesbill
Family Name: Geraniaceae
Origin: South Africa; parent origin not confirmed at time of posting.
Positioning: Foreground, forest edge, ground cover underplanting
Garden Themes: Perennial, woodland, rock, cottage, pollinator
Uses: Edging, borders, mass, containers
Type: Herbaceous perennial
Size: 18" tall and spreading
Outstanding Feature(s): Flower
Color: Medium to light green, may turn red/orange/yellow in autumn.
Flower: Spring to Autumn. Open cymes, slightly cupped blue-violet. Showy.
Fruit: May produce seed with the appearance of a cranes bill.
cultural requirements, tolerances & problems
Sunset Zones: A2, A3; 2-9, 14-24
USDA Zones: 4-8
Light: Sun (coastal), light shade to partial shade (inland)
WUCOLS SF Bay Area Hydro Zone: Moderate
Texture: Sand, loam, clay, chalk, well composted
Moisture Retention: Well-drained
pH: Slightly acidic to alkaline
Tolerances: Dear, drought
Branch Strength: N/A
Insects: Vine weevil
Disease: Leaf spot, rust, powdery mildew
citations & attributions
Bayton, R. (2019). The Royal Horticultural Society's the Gardener's Botanical: An Encyclopedia of Latin Plant Names. London: Mitchell Beazley.
Norris Brenzel, K. (Ed.). (2012). The New Sunset Western Garden Book. New York: Time Home Entertainment, Inc.
Plant Finder. "Geranium 'Johnson's Blue'." Missouri Botanical Garden, St. Louis. Accessed on August 30, 2021, from https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=d101.
RHS. "Geranium × johnsonii 'Johnson's Blue'." The Royal Horticulture Society, London. Accessed on August 30, 2021, from https://www.rhs.org.uk/Plants/95458/Geranium-Johnson-s-Blue/Details.
Water Use Classification of Landscape Species. "WUCOLS IV Plant List." University of California, Division of Agriculture and Natural Resources, Davis. Accessed on July 27, 2021.
Feature flower photos: Purchased from Shutterstock
Geraniums with topiaries: "Jardins de Crathes Castle (XXe siècle), Banchory, Aberdeenshire, Ecosse, Grande-Bretagne, Royaume-Uni." by Bernard Blanc is licensed under flickr.