Most of us have grown perennial cranesbills (hardy Geranium) at one time or another. Not to be confused with pelargonium, the ubiquitous houseplant and scented foliage varieties known colloquially as simply “geraniums”. Cranesbills are so common, we frequently dismiss them as not worth our attention. Add to their familiarity a reputation for erratic performance, and it’s easy to see why cranesbills aren’t as popular as they could be. I’m willing to bet most of us have had at least one unsatisfying experience– I certainly have.
It doesn’t help that so many cranesbills look similar. You might assume they’re all pretty much the same. Yet cranesbills have proven time and again they’re not as interchangeable as growers would have you believe. That’s not the plant’s fault. As with any family, individual varieties are unique and perform accordingly. The problem lies with the sellers, who don’t provide enough information, and ourselves, who prefer our plants to require the lowest maintenance possible.
As a result, aside from choice cultivars like Rozanne and Johnson’s Blue, cranesbills often disappoint. We expect them to provide nonstop color all summer with no care from us. Instead they sprawl, they stall, quit flowering, flop, and entangle.
What’s a gardener to do?
First let’s dispel a few myths.
Fact or Fiction?
Cranesbills bloom all summer long. “
Not quite; a few do. This is maybe the biggest misconception out there. While top cultivars Rozanne and Johnson’s Blue are hyped as blooming for “months” and “spring till frost”, that is only with a hard cut-back after the first flush and touch-up pinches the rest of the season. It’s also under optimal conditions like morning sun and afternoon shade, with no extreme heat or drought to halt flowering.
Mostly, the average bloom time depends on the cultivar. Some are only in flower for a short period, usually late spring. Many lovely choices fall into this group. If you see a variety you want, find out its bloom period. I’m not suggesting you pass it by, but avoiding disappointment is always helpful.
Cranesbills respond to pinching and pruning.”
Yes, they do. In fact doing this one thing is a necessity if you want maximum flower output from a cranesbill. To stimulate another flush of flowers and encourage bushiness, cut the plant back to remove any developing seedheads after the intial flush, usually in early summer. Most will reflower either sporadically or with a second flush, maybe a third if it’s a warm autumn and you keep at it. No promises, but pinching never hurts.
Deadheading helps too, if you’ve got the patience. The groundcover types, though, don’t benefit from deadheading. But generally you do need to pinch, pinch, pinch.
Fertilizing will produce more flowers.”
Probably not. Cranesbills will grow in almost anything, but many prefer soil on the leaner side as opposed to a rich fertile mix. A neutral to slightly alkaline ph should yield the best bloom-to-foliage ratio. Fertilizing tends to spur foliar growth as much as flower output, so while you’ll certainly get a larger plant with fertilization, the ratio of flowers to foliage won’t necessarily improve.
And, the more fertile the soil, the more sprawling and flopping you can expect, particularly with the larger cultivars. Feed cranesbill only if the plant is young, undersized or weak; a light fertilization in spring is usually sufficient. Otherwise, hold back.
While most cranebills appreciate modest moisture, try allowing the soil to dry out completely between waterings (unless it’s scorching hot). If that doesn’t help, then fertilize lightly with a formulation designed to encourage flower development, not foliage. That is, low nitrogen.
Despite cranesbills’ relatively long bloom periods, the coverage per plant is rarely prolific. They max out their flower-to-foliage ratio at 60%, with 40% more common. This might mean a light sprinkling of blooms is all you’ll ever get from some cranesbills, even at peak production. Over 60% of the foliage covered by the flowers is exceptional.
So, if your cranesbill is healthy but flowering modestly, that may be perfectly normal. This is why cranesbill works best as a supporting cast member, not the star of the show. It’s a filler, a spiller, a knitter.
Finally, cultivars with the smallest flowers often produce the highest quantity at once; when it comes to bloom size, larger doesn’t always mean better.
Full sun is best for cranesbills.”
Not necessarily. Most cranesbills tolerate full sun and thrive, especially if the weather isn’t scorching. But high heat in full sun is another story. Excessive heat can halt or cut short flower production, not just in cranesbills but in numerous species. The plant must focus on survival under stress, and the best way to do that is to quit flowering.
To help offset this tendency, cranesbills actually prefer some afternoon shade in hotter conditions, and a few shade-loving cultivars need a half day of shade or more. This is especially true of the woodland varieties. If your cranesbill is under-performing in full sun, try moving it to a moist spot with some shade, preferably afternoon shade.
If full sun is all you’ve got, Max frei or Ann Folkard are good choices. They take the heat quite well (with supplemental watering) while flowering. Max Frei will take a break in midsummer, usually blooming lightly again in late summer into fall.
Deer leave cranesbills alone.”
The unsatisfying truth is, it depends. Deer are notorious opportunists who will sample anything when they are hungry enough. In my garden the deer ignore most cranesbills but not all. They don’t touch Rozanne or Max frei, for instance. Unfortunately they absolutely love the cultivar Brookside, my Armenian cranesbill and all the woodland varieties.
It doesn’t help (for long) to spray them with repellant or plant them with unpalatable companions. I could net them but don’t, as they are scattered throughout the garden. I’ve simply resigned myself to total demolition most of the time, and consider myself lucky when one manages to survive and somehow bloom.
The truth is, you won’t know for sure if deer will leave a particular cranesbill alone until you try it.
Cultivars to Consider
Most cranesbills are native to high alpine areas across the wider Mediterranean region, so they are reliably cold hardy. Some grow tall and others short, but all produce a pointed seedpod after flowering that resembles a crane’s long pointy bill — hence their common name. This is what you want to pinch off to encourage more flowers instead of seeds.
Bloom colors are white, pink, purple or blue. Foliage is roughly maple-leaf shaped, often deeply lobed or incised. So-called “bloody cranesbills” (sanguineum varieties) have foliage which turns shades of red in fall. While local nurseries typically carry just a few selections, if you want something different, Digging Dog Nursery in California lists no less than 70 cranesbills in its 2023 mail order catalog. Now that’s impressive!
Here are just a few, starting with the ones I grow. (Or try to, the deer notwithstanding).
Rozanne – Considered best in class, Rozanne is the most popular cranesbill grown today. Its rich lavender-blue, quarter-sized blossoms have a small white center and dark stamens. Robust and sprawly, Rozanne grows 1 to 2 feet tall and up to 3 feet wide or more. Pinch or cut back regularly to contain it, or let it twine into its neighbors if that’s your thing. Rozanne may take a break in the worst of the heat but she reblooms right up until frost here. Hardy, readily available, reliable.
Johnson’s Blue was the go-to cranesbill for decades before Rozanne came along. A bit smaller and as lovely as ever! The color is bluer than Rozanne but flowering is erratic after the first flush. It can be a bit floppy but responds well to periodic trims. Johnson’s is getting hard to find but it’s still worth seeking out. Stunning paired with Max frei as in my neighbor’s front bed, or with any number of other choices. A useful cranesbill in a captivating color.
Max frei – This dwarf selection has a neat mounded habit only 6 to 8 inches high and a foot across, a long bloom period, lacy foliage and eye-popping color. Blooms early and reliably. Max is one of the best for full sun. Penny-sized fuschia cups provide excellent coverage and saturated, unfading color. Top-notch for edging and rock gardens. Landscape designers love it. (Me too!) A manual hedge trimmer is helpful when deadheading. Max frei will take a break in midsummer with sporadic fall rebloom. The foliage turns burgundy-red as well.
Brookside – A personal favorite. This beauty has quarter-sized violet-blue flowers with strong veins and attractive foliage. Purportedly it gets 30 inches tall and wide, but mine have yet to surpass twelve inches, courtesy of the deer. It supposedly repeat blooms, but since mine get munched constantly I haven’t been able to evaluate it properly. The veining, rich color and fused petals make for a winning combination. If you are lucky enough to be deerless, do try it. I’m starting to see our local nurseries carrying it finally. Hopefully it will become easier to find.
Dusky Cranesbill – Also called Samobor. An unusual cranesbill valued as much for its leaves as flowers, held high above the foliage on upright stems. Nickel-sized plum blooms gently reflex with age. Nice for woodsy edges; give it part shade. A strong grower, it should rebloom sporadically with deadheading. Near-black patterned bands on the lobed foliage is reminiscent of heuchera. For this reason it looks good all season long.
Here are some others of note. I haven’t grown most of these myself.
Raven – Another deep purple reflexed cranesbill with plainer foliage than Samobor. I don’t know anything about this one but it’s an intriguing choice. One drawback of small dark flowers is they don’t show up very well. To help them stand out, provide paler companions or place in a prominent position where they won’t get lost.
Espresso – Also called Spotted Cranesbill, a nativar derived from our native wild geranium maculatum. I tried Espresso a few years back but was less than enthralled, primarily because I had the wrong expectations of it — I thought it would repeat bloom. It does not.
Espresso’s foliage is a blah bronzy olive (not chocolate as hyped), about 18 inches tall by 12 inches wide, with pale pink flowers. The quiet coloring causes the entire plant to visually fade into the background unless you place it carefully. Very delicate with a 6-week spring bloom period, it’s neither showy nor a rebloomer; it’s a shy wildflower really, but a sophisticated choice nonetheless. Just be aware of this so it doesn’t disappoint.
Boom Chocolatta and Dark Reiter – Other hybrids with dark foliage. I haven’t grown either of these but they look promising. Judging by their photographs they have good bloom color, substantial presence, and excellent flower coverage. If anyone has grown these, please tell us about your experience in the comments!
Splish Splash – A novelty selection with bicolored petals. Despite the attractive markings, I imagine the flowers “read” as white in a garden setting. Unique, though. Has anyone tried Splish Splash?
St. Ola – Here’s an older cranesbill originating from a different subspecies. St. Ola is an 8 to 14 inch tall X 24 inch wide plant suitable for use as a ground cover. Thanks to its bright white coloring it has a fresh look. St. Ola can take full sun but prefers a bit of shade and some moisture. The slightly reflexed flowers take on a pink blush. Lightly shear the entire plant after flowering to encourage a modest rebloom.
Ann Folkard – The best of the deep magenta hybrids, this robust improvement on Armenian cranesbill will boldly knit together its neighbors. Intensely colored small cups with a black center make for a striking presence on a 2 foot X 3 foot plant. Provide moist, sunny to part shady conditions. Paired with the right companions, Ann Folkard is a color machine you’ll surely want in your garden.
Geranium maculatum (wild geranium) – This wildflower is native to the Midwest and Eastern US. It’s commonly found in woodlands and shady roadsides. (Deer love it.) The flowers are a soft lilac-pink, and it blooms in spring for about 6 weeks if the deer don’t find it. Nice to have in a woodland garden, but ephemeral as it soon recedes into the greenery of summer with no rebloom.
Remember, this is just a small sampling. There are dozens of choices if you seek them out. Do consider growing cranesbill if you’re not already, and start pinching those sprawly stems to beef up flower production. Mass them, twine them, spill them, pair them.
Need a low carpet of color? An edging by a walkway? Something to hide the feet of lilies or roses or anything, really? Cranesbills are perfect.
Something has eaten my Rozanne down to the nubbies. It was planted last spring and something (bunnies? deer? groundhog?) “pruned” it all season so the blooms were few. This year they started early. I ended up moving it to the front yard in hopes that it won’t be found. Although I had all the same critters at my last house, nothing ate it. Sigh.
I’m sorry to hear that, Kate! My money is on the deer. Good luck.