Geraniums - Chicago Botanic Garden

plant-trial results | EXPERT TESTED

Geraniums
The best
of the best
After testing 180 varieties for
15 years, the results are in
By Richard Hawke
Rozanne
geranium

Geraniums (Geranium spp. and cvs, Everything you need
USDA Hardiness Zones 3–8) are to know about geraniums
terrific. It really is that simple. We
could talk about their landscape versatility, ▶ Don’t get them confused with their cousins
cultural adaptability, and superior ornamen- True geraniums (Geranium spp. and cvs.) are often referred to as “hardy
tal traits. Or we could talk about their sheer geraniums” to distinguish them from their tender cousins: the colorful bed-
variety: There are about 300 species and ding (or zonal) geraniums (Pelargonium spp. and cvs., top right). An alter-
a plethora of cultivars and hybrids in the nate common name of true geraniums, cranesbill, is a nod to their slender
world. But geraniums are simply awesome fruit, which resemble the beak of a crane.
garden plants because of their beauty and
their tried-and-true reputation. Despite ▶ The foliage can be as cool as the flowers
these good traits, there are, unfortunately, a Most geraniums have attractive foliage, and although quite
few less-than-stellar varie­ties out there, and variable, their leaves are generally lobed and often deeply
nobody wants to be the one to spend their dissected. Leaf colors range from bright green to gray-green,
money on a stinker. That is why I decided but there are a number of varieties that have purple, bronze,
to put more than 180 of them to the test, or yellow leaves. Many, however, don’t hold their foliage color
and you’ll find my conclusions on many of throughout the season. We had the best success with Victor
those trialed in the pages that follow. Reiter strain, a seed strain of meadow geranium (G. pratense)
that loses its deep purple leaf color in midsummer but turns
My love of geraniums began when I first purple again in fall.
saw the luminous flowers of ‘Johnson’s Geraniums can bloom from spring to autumn for a few weeks
Blue’, certainly one of the most well- or many months, depending on the variety. While the blue-
known and beloved cultivars of all time. flowered selections seem to be de rigueur for modern gardens,
But when I trialed it, I found ‘Johnson’s geraniums come in pink, magenta, purple, and white. The som-
Blue’ to be a lax plant with a penchant for ber, near-black blossoms of the aptly named mourning widow
floppiness and a fairly short bloom period. geranium (G. phaeum, left) are some of the most interesting.
Although it was the go-to blue geranium
for many years, it has been surpassed by an ▶ Trim them back for a better habit
array of newer and more exciting selections. Although geraniums are not high-maintenance plants, most
must be cut back after flowering. Shearing stems back to new
Until we started our trial, my familiarity basal leaves reins in unruly habits and rejuvenates plants to
with geraniums—aside from the most popu- an almost springlike quality. There are a few exceptions to this
lar garden staples—was somewhat lacking. rule: Bigroot geranium (G. macrorrhizum), Cambridge geranium
But I know gardeners who, astonishingly, (G. × cantabrigiense), bloody geranium (G. sanguineum), and
have never grown a single geranium. Perhaps Wlassov’s geranium (G. wlassovianum) do not need shearing
that is because there are so many to choose after flowering. You can also skip the shearing on late-
from—maybe too many. I also wonder if blooming creeping geranium (G. soboliferum) and ever­
gardeners just assume that geraniums are all blooming Rozanne geranium (G. ‘Gerwat’). Deadheading
the same or if the overp­ opularity of a few also reduces self-seeding, which can be excessive.
select varieties has created a comfort zone
that keeps gardeners from straying off the ▶ Color doesn’t end when the flowers do
path. After 15 years of testing, I’ve thank- Come autumn, many geraniums turn shades of purple, red,
fully discovered a vast trove of indispensable orange, or yellow—and often on the same plant (right). Cambridge
geraniums—as well as a few that I wish I’d geranium and bigroot geranium are among my picks for the best
never laid eyes on. autumnal displays.

▶ They’re not picky about conditions
Geraniums are generally easy to grow in a variety of light conditions
from full sun to full shade and in most soils, except those that are
overly wet or too dry. Rich, moist soil is ideal for most geraniums—
even drought-tolerant species, such as bigroot geranium. Morning
sun will encourage stronger habits and better flower production
on shade-loving geraniums, and will enhance leaf color on bronze-
leaved forms, like ‘Elizabeth Ann’ and ‘Espresso’. In hot regions,
afternoon shade is priceless in keeping geraniums happy and healthy.

▶ Pests and diseases plague only some types
Geraniums are rarely troubled by diseases or pests, but powdery mildew, leaf spot-
ting, rabbits, and Japanese beetles are occasional problems. Powdery mildew was
notable on cultivars of meadow geraniums only, while Japanese beetles found the
many cultivars of Druce’s geranium (G. × oxonianum) delectable. And mourning
widow geraniums, especially ‘Margaret Wilson’, proved to be irresistibly succulent
treats for rabbits.

www.finegardening.com | June 2012 39

How we did ‘Orion’
the trial

• N umber
evaluated: 180

• Criteria: Orna­
mental qualities,
ease of growth, har­
diness, and disease
and pest resistance

• USDA Hardiness
Zone: 5b

• Conditions: In
our full-sun trial
garden (with well-
drained, alkaline,
clay-loam soil) or in
our shade trial gar­
den (with dappled
shade from nearby
trees and moist,
well-drained soil)

• Care: Minimal,
thereby allowing
the plants to
thrive or fail under
natural conditions

40 Fine Gardening | www.finegardening.com

Top performers

Rozanne (‘Gerwat’, photo, p. 38) is unquestionably Bigroot
the most popular geranium today and certainly geranium
deserving of the accolades it has received, including
Photos (pp. 38–43), except where noted: Doreen Wynja; p. 38, Dave Zubraski/www.gapphotos.com; p. 39 (top), Steve Aitken; p. 39 (center), the 2008 Perennial Plant of the Year and Royal ‘Brookside’
Dency Kane; p. 39 (bottom), Jerry Pavia; p. 40, Martin Hughes-Jones/www.gapphotos.com; p. 41 (top), www.millettephotomedia.com Horticultural Society’s Award of Garden Merit. The
white-eyed, purple-blue flowers are not always pres-
ent in great quantities, but the plant is perpetually in
bloom. I’m especially fond of the iridescent flowers in
autumn, when cool weather sets in and not much else
is blooming. Rozanne’s large, mounded habit with
trailing flower stems is well suited to massing, but a
single plant shines on its own, too. Because the flow-
ers are sterile, they do not produce seed and, there-
fore, bloom for an extended time. In my garden, I
grow Rozanne with the lavender-and-creamy-white
blossoms of ‘Mrs. Robert Brydon’ clematis (Clematis
‘Mrs. Robert Brydon’, Zones 4–9); this sublime pairing
is a hit for several weeks in late summer.

Everything about ‘Orion’ is supersize—from the
abundance of the nearly 2-inch-wide, purple-blue
flowers to its robustly spreading stems. At 30 inches
tall and 6 feet wide, ‘Orion’ is a bit of a bruiser,
topping the list as the largest geranium in the trial.
Despite its size, ‘Orion’ never seems bulky, thanks
to its fine-textured, dissected leaves. Like many
geraniums, new leaves emerge as flowering winds
down, ultimately pushing the floral stems away from
the new growth. This is your cue to shear the old
stems back to the base and to let the new leaves
have their day.

It’s true that I have quite a few favorites when it
comes to geraniums, but if pushed to choose just one
for my garden, I would likely pick bigroot geranium
(G. macrorrhizum). It’s one of the easiest plants I
know of to grow: It is adaptable to sun or shade, is
drought tolerant, and doesn’t need shearing. And it’s
beautiful, too, with magenta-pink to white flowers in
spring; lush foliage that turns red, orange, and bur-
gundy in fall; and a refined spreading habit. Some
of its many cultivars have unique flower colors—
including ‘Lohfelden’, which has elegant, soft pink
blooms, and ‘Czakor’, which boasts lusty, deep
magenta blossoms. Bigroot geraniums are easily dis-
tinguished from other species by their slightly sticky,
aromatic foliage; the scent is variably described as
“minty,” “medicinal,” or “malodorous.”

Although it is no longer the most popular geranium in
town, I still love ‘Brookside’. In our trial this variety
had a compact, well-mannered habit that was far
superior to the floppy ‘Johnson’s Blue’. In my own
garden—where it gets more competition—‘Brookside’
is a bit rambunctious, but the pretty pale-eyed flowers
are still delightful as the stems weave and wind
through their neighbors. The flowers are reminiscent
of ‘Johnson’s Blue’ but are darker with overlapping
petals. Once ‘Brookside’ has finally exhausted itself in
midsummer, I cut the stems back hard to encourage
new leaves. An added bonus are the finely dissected
leaves, which turn red and burgundy in autumn.

continued on page 44 ➨

Geranium trial results

Rating Name exposure Height Width Flower Color Flower Bloom Period Flower
Size (DIA.) Coverage

To see more results from the geranium trial, go to FineGardening.com/Geraniums. « Geranium ‘Ann Folkard’ Full sun to partial shade 18 inches 36 inches Dusky purple 1½ inches  Midspring to midsummer Good
«««« G. ‘Blue Cloud’ Full sun to partial shade 26 inches 40 inches Pale lavender-blue
««« G. Blue Sunrise (‘Blogold’) Full sun to partial shade 24 inches 36 inches Lavender-blue 1¼ inches Midspring to midsummer Good Rating
«««« G. ‘Brookside’ Full sun to partial shade 24 inches 38 inches Lavender-blue Good key
««« G. × cantabrigiense ‘Biokovo’ Full sun to full shade 9 inches 20 inches White, pink blush 1¼ inches Late spring to midsummer Good
««« G. × cantabrigiense ‘Cambridge’ Full sun to full shade 9 inches 21 inches Deep pink Good ★★★★ Excellent
««« G. × cantabrigiense ‘Jans’ Full sun to full shade 10 inches 50 inches White, pink blush 1½ inches Midspring to late summer Good ★★★ Good
«««« G. × cantabrigiense ‘St. Ola’ Full sun to full shade 10 inches 43 inches White Good ★★ Fair
« G. clarkei ‘Kashmir Purple’ Full sun to partial shade 15 inches 20 inches Purple 1 inch Midspring to early summer ★ Poor
««« G. ‘Dilys’ Full sun to partial shade 14 inches 48 inches Light magenta
«« G. gracile Full shade 10 inches 15 inches Lavender-pink 1 inch Midspring to late spring
««« G. himalayense Full sun to partial shade 15 inches 30 inches Blue
««« G. himalayense ‘Baby Blue’ Full sun to partial shade 13 inches 31 inches Lavender-blue 1 inch Midspring to early summer
««« G. himalayense ‘Gravetye’ Full sun to partial shade 15 inches 30 inches Blue
«« G. himalayense ‘Irish Blue’ Full sun to partial shade 15 inches 24 inches Lavender-blue 1 inch Midspring to early summer Good
««« G. ibericum ‘Rosemoor’ Full sun 12 inches 18 inches Violet-blue
««« G. ibericum ssp. jubatum ‘Vital’ Full sun 14 inches 22 inches Purple 1¼ inches Midspring to early summer Poor
««« G. ‘Johnson’s Blue’ Full sun to partial shade 24 inches 33 inches Blue
««« G. macrorrhizum Full sun to full shade 14 inches  32 inches Magenta  1 inch Midspring to midsummer Fair
««« G. macrorrhizum ‘Czakor’ Full sun to full shade 12 inches 36 inches Dark magenta
««« G. macrorrhizum Full sun to full shade 14 inches 42 inches Light pink 1 inch Midspring to midsummer Poor
‘Ingwersen’s Variety’
«««« G. macrorrhizum ‘Lohfelden’ 1½ inches Midspring to early summer Good
«« G. macrorrhizum ‘Pindus’
««« G. macrorrhizum ‘Ridsko’ 2¼ inches Midspring to early summer Fair
««« G. macrorrhizum ‘Variegatum’
««« G. maculatum ‘Beth Chatto’ 2 inches Midspring to early summer Good
««« G. maculatum ‘Elizabeth Ann’
««« G. maculatum ‘Espresso’ 2 inches Midspring to early summer Fair
«« G. maculatum f. albiflorum
«««« G. ‘Moran’ 1½ inches Late spring to early summer Good
««« G. ‘Nimbus’
«««« G. ‘Orion’ 1½ inches Midspring to late spring Good
««« G. × oxonianum ‘A. T. Johnson’
1½ inches Midspring to early summer Good

1 inch Midspring to late spring Good

1 inch Midspring to late spring Good

1 inch Midspring to late spring Good

Full sun to full shade 8 inches 18 inches Very pale pink 1 inch Midspring to early summer Excellent
Full sun to full shade 10 inches 22 inches Magenta-pink 1 inch Midspring to early summer Fair
Full sun to full shade 14 inches 32 inches Magenta-pink 1 inch Midspring to early summer Fair
Full sun to full shade 17 inches 34 inches Rosy pink 1 inch Midspring to early summer Good
Partial shade 13 inches 21 inches Pink 1½ inches Early spring to midspring Good
Partial shade 22 inches 30 inches Lavender-pink 1¼ inches Early spring to early summer Good
Partial shade 18 inches 27 inches Lavender-pink 1¼ inches Early spring to midspring Good
Partial shade 15 inches 21 inches White 1¼ inches Early spring to late spring Fair
Full sun 24 inches 26 inches Violet-blue 1¼ inches Early spring to late spring Excellent
Full sun to partial shade 24 inches 36 inches Purple-blue 1 inch Midspring to late summer Good
Full sun to partial shade 30 inches 72 inches Purple-blue 1¾ inches Midspring to late summer Excellent
Full sun to partial shade 17 inches 25 inches Pink 1¼ inches Midspring to late summer Good

«« G. × oxonianum ‘Claridge Druce’ Full sun to partial shade 16 inches 27 inches Violet-pink 1½ inches Midspring to early summer Poor
««« G. × oxonianum ‘Lady Moore’ Full sun to partial shade 17 inches 24 inches Pink 1¼ inches Midspring to midsummer Good
«« G. × oxonianum ‘Phoebe Noble’ Full sun to partial shade 16 inches 30 inches Dark pink 1¼ inches Midspring to early summer Fair
««« G. × oxonianum ‘Rebecca Moss’ Full sun to partial shade 22 inches 36 inches Silvery pink 1¼ inches Midspring to late summer Good

« G. × oxonianum ‘Rose Clair’ Full sun to partial shade 19 inches 22 inches Rose-pink 1½ inches Midspring to early summer Poor
««« G. × oxonianum Full sun to partial shade 17 inches 26 inches Pale pink Good
‘Southcombe Star’ 1 inch Midspring to late summer
«« G. × oxonianum ‘Wargrave Pink’ 24 inches
««« G. palustre Full sun to partial shade 14 inches 45 inches Pink 1½ inches Midspring to early summer Fair
« G. ‘Patricia’ Full sun to partial shade 12 inches 24 inches Magenta-pink 1¼ inches Midspring to midsummer Fair
«« G. phaeum ‘Lily Lovell’ Full sun 18 inches 28 inches Magenta 1½ inches Midspring to early summer Fair
««« G. phaeum ‘Margaret Wilson’ Full sun to partial shade 14 inches 27 inches Maroon ¾ inch Midspring to late spring Fair
«« G. phaeum ‘Samobor’ Full sun to partial shade 13 inches 20 inches Purple w/ white eye ¾ inch Midspring to late spring Good
«« G. ‘Philippe Vapelle’ Full sun to partial shade 15 inches 18 inches Maroon ¾ inch Midspring to late spring Fair
««« G. platypetalum Full sun 16 inches 25 inches Blue-violet 1½ inches Midspring to late spring Fair
«« G. pratense Full sun to partial shade 16 inches 12 inches Violet-blue 1¾ inches Midspring to early summer Excellent
Midnight Reiter strain Full sun 8 inches Purple-blue 1½ inches Midspring to midsummer Fair
««« G. pratense ‘Mrs. Kendall Clark’ 38 inches
««« G. pratense ‘New Dimension’ Full sun 24 inches 33 inches Lavender-blue 1¼ inches Midspring to early summer Fair
«« G. pratense ‘Plenum Violaceum’ Full sun 11 inches 30 inches Lavender-blue 1¼ inches Late spring to midsummer Good
««« G. pratense Victor Reiter strain Full sun 18 inches 21 inches Violet-blue 1 inch Late spring to midsummer Fair
« G. psilostemon Full sun 14 inches 24 inches Purple-blue 1½ inches Midspring to midsummer Good
«« G. psilostemon Full sun 12 inches 30 inches Dark magenta 2 inches Midspring to midsummer Fair
‘Bressingham Flair’ Full sun 26 inches Light magenta 2 inches Midspring to midsummer  Fair
« G. renardii 18 inches
www.finegardening.com | June 2012 «« G. renardii ‘Zetterlund’ Full sun 7 inches 15 inches White and lavender 1½ inches Midspring to late spring Fair
«««« G. Rozanne (‘Gerwat’) Full sun 11 inches 60 inches Lavender 1¼ inches Midspring to late spring Fair
««« G. sanguineum ‘Aviemore’ Full sun to partial shade 20 inches 26 inches Purple-blue 1½ inches Early summer to late fall Good ‘Ann
««« G. sanguineum ‘Canon Miles’ Full sun 10 inches 36 inches Purple 1¼ inches Midspring to midsummer Good Folkard’
««« G. sanguineum ‘Connie Hanson’ Full sun 12 inches 24 inches Purple-pink 1 inch Midspring to midsummer Good
43 ««« G. sanguineum ‘Elke’ Full sun 20 inches 36 inches Light pink 1¼ inches Midspring to midsummer Good
««« G. sanguineum ‘Elsbeth’ Full sun 20 inches 32 inches Dark pink 1¼ inches Midspring to midsummer Good
««« G. sanguineum ‘Kristin Jakob’ Full sun 20 inches 34 inches Magenta 1½ inches Midspring to midsummer Good
«« G. sanguineum ‘Max Frei’ Full sun 14 inches 29 inches Purple-magenta 1 inch Early spring to midsummer Good
««« G. sanguineum ‘New Hampshire’ Full sun 12 inches 32 inches Magenta-pink 1 inch Midspring to midsummer Fair
««« G. sanguineum ‘Rod Leeds’ Full sun 20 inches 60 inches Magenta 1½ inches Midspring to midsummer Fair
«« G. sanguineum var. striatum Full sun 20 inches 25 inches Magenta 1¾ inches Late spring to midsummer Good
« G. soboliferum Full sun 11 inches 22 inches Pale pink 1¼ inches Early spring to midsummer Fair
««« G. ‘Spinners’ Full sun to partial shade 12 inches 30 inches Purple 1½ inches Midspring to midsummer Fair
««« G. ‘Sweet Heidy’ Full sun to partial shade 20 inches 72 inches Purple-blue 1½ inches Midspring to midsummer Fair
««« G. sylvaticum ‘Baker’s Pink’ Full sun 20 inches 18 inches Purple w/ pale eye 1½ inches Late spring to late fall Good
« G. sylvaticum ‘Nikita’ Full sun to partial shade 18 inches 18 inches Pink 1¼ inches Midspring to late spring Good
««« G. sylvaticum ‘Silva’ Full sun to partial shade 10 inches 18 inches Violet 1½ inches Early spring to late spring Poor
««« G. ‘Tiny Monster’ Full sun to partial shade 15 inches 54 inches Violet 1½ inches Early spring to late spring Good
««« G. wallichianum Full sun 18 inches 48 inches Magenta 1½ inches Late spring to late fall Good
‘Buxton’s Variety’ Full sun to partial shade 16 inches Purple-blue 1½ inches Late spring to late fall Good
««« G. wlassovianum 36 inches
Full sun to partial shade 20 inches Purple 1¼ inches Late spring to early fall Good

Top performers

Standing out in a field of blue-flowered geraniums
requires a little something extra. Golden chartreuse
leaves flushed with red are just the thing that set Blue
Sunrise (‘Blogold’) apart. The vibrant spring leaf color,
which is enhanced in sunlight, fades to yellowish green
just as the lavender-blue flowers open in late spring.
Blue Sunrise is believed to be a hybrid of yellow-leaved
‘Ann Folkard’ (photo, p. 43) and blue-flowered ‘Buxton’s
Variety’ geranium (G. wallichianum ‘Buxton’s Variety’).

‘Sweet Heidy’ is touted for its unique tricolored
flowers of lavender-blue, pink, and white. But that’s a
somewhat deceptive description because the three
colors aren’t present on the flower at the same time.
The fresh flowers are pinkish purple with a pale eye,
and as they age, the purple morphs into a bluish
color. Quibbling about the flower color does not
lessen the remarkable floral display because the
blooms are plentiful from late spring into fall. ‘Sweet
Heidy’ looks like a pink-flowered Rozanne because of
its mounded habit and trailing stems. The rambling
stems enable this plant to look great in hanging bas-
kets, in containers, or dangling over low walls.

At first glance, ‘Elizabeth Ann’ (G. maculatum
‘Elizabeth Ann’) is extremely similar to ‘Espresso’

Blue Sunrise ‘Elizabeth
Ann’
Photos (pp. 44–45): p. 44 (left), Richard Bloom/www.gapphotos.com; p. 44 (right), Nancy J. Ondra; p. 45
(top left), Ron Evans/www.gapphotos.com; p. 45 (top right), FhF Greenmedia/wwwgapphotos.com; p. 45
(center right), courtesy of www.songsparrow.com; p. 45 (bottom right), courtesy of Luc Klinkhamer

New kids on the block

‘Sweet Plant breeders can’t get enough of geraniums. ‘Starman’
Heidy’ Just when you think you’ve seen every cultivar out ‘Butterfly Kisses’
there, another crop is introduced. Some of these new ‘Perfect Storm’
geranium, but in the end, I prefer ‘Elizabeth Ann’ for its selections are fleeting, but others are showing enough
superior floral and foliar qualities. Its lavender-pink promise in their first few years of trialing that I believe
flowers with nicely overlapping petals are significantly they deserve a bit of press.
darker than ‘Espresso’. Both cultivars have distinctive,
chocolatey bronze–colored leaves in spring, which Because it blooms out of sequence from most
eventually fade to a summer mix of bronze and green. other geraniums, ‘Starman’ creeping geranium
But the more lustrous leaves of ‘Elizabeth Ann’ bring (G. soboliferum ‘Starman’) was a bit of a sleeper; it
an unexpected brightness to a shady garden. Both wasn’t until the second year that I realized it was
cultivars reseed plentifully and appear to come true something special. It is a prolific late bloomer—not
from seed, but they express some seedling variability, starting until late summer—with a charming two-
too; we discovered a number of seedlings, for exam- toned flower. The 1½-inch-wide purple flowers are
ple, with superior leaf color to either cultivar. patterned with darker veins and marked with a promi-
nent starburst in their centers. ‘Starman’ has a refined
Richard Hawke is the plant evaluation manager at the mounded habit (16 inches tall and 36 inches wide)
Chicago Botanic Garden in Glencoe, Illinois. all summer and doesn’t need deadheading. It tops
off the impressive floral show with respectable red
fall color, too.

Given my newfound appreciation for ‘Starman’,
I was jazzed about evaluating ‘Butterfly Kisses’
creeping geranium (G. soboliferum ‘Butterfly
Kisses’). Like ‘Starman’, ‘Butterf­ly Kisses’ is equally
prodigious in bloom but begins flowering a week or
so later (at the very end of summer) and carries on
well into late fall. The 1½-inch-wide, light purple-pink
flowers are without a starry eye; each blossom is,
instead, beautifully striated with prominent red-purple
veins. ‘Butterfly Kisses’ is slightly bigger (20 inches
tall and 50 inches wide) than ‘Starman’ and does
show off some red and orange fall color.

I’m usually reticent to talk about plants that have just
begun their trial, but I’m quite taken by ‘Perfect
Storm’, a new introduction with pretty, dark-eyed,
magenta-pink flowers. Dramatic, dark purple veins
burst from the smoldering black eye, giving the plant
a singular exuberant look. Last year, ‘Perfect Storm’
was in constant bloom from spring to late fall, with
handsome, downy, gray-green leaves complementing
the eye-catching flowers. The low-growing plant
(8 inches tall and 24 inches wide) has trailing stems
radiating out from the mounded crown. I imagine that
‘Perfect Storm’ cascading over a stone wall or in a
hanging basket would be perfection.

[ SOURCES ]
The following mail-order plant sellers offer many of the geraniums featured:
• Digging Dog Nursery, Albion, Calif.; 707-937-1130; www.diggingdog.com
• Geraniaceae.com, Kentfield, Calif.; 415-461-4168; www. geraniaceae.com
• Lazy S’S Farm Nursery, 2360 Spotswood Trail, Barboursville, VA 22923;

www.lazyssfarm.com

www.finegardening.com | June 2012 45