Report from the trial beds: Erodium!

Erodium is one of those genera that I had vaguely heard of but didn't really know anything about before I started working at Arrowhead. They're closely related to Pelargoniums, and I'd always sort of assumed they wouldn't be very winter hardy. But they're proved me wrong on the hardiness front, and now, the more I see of them, the more I like them. The ones we grow all bloom continuously starting now in late spring and continuing on without a pause well into the fall. The flowering is never super heavy – these aren't plants that smother themselves with flower – but that is more than compensated for (at least in my mind) by the intricate beauty of the flowers and the absolutely terrific ferny foliage. Also a huge plus, so far the deer and rabbits haven't shown any interest in them (though I'm making no guarantees... if your critters are hungry enough they'll eat almost anything) and they absolutely laugh at drought, heat AND our cold, cold winters.

Erodium chelianthifolium

Erodium glandulosum

Erodium glandulosum and E. chelianthifolium are two of my favorites, and I'm totally geeked that they sailed through our solidly zone 5 winter without missing a beat. Both form compact, tidy mounds (at one year in, they're 3-4 inches tall, and maybe 6 inches wide) of beautiful silver, finely cute fern-like foliage and have delicate round pale pink (in the case of ) or white (in the case of ) flowers with a pansy-like eye of darker purple that dance above the leaves on slender stems.

Erodium glandulosum

Erodium chelianthifolium

The two species are quite similar, with E. glandulosum somewhat larger in all its parts and proving to be marginally more vigorous and heavily blooming in the garden, though I think E chelianthifolium. has somewhat prettier (though smaller) blooms, and a stronger silver to the foliage.

Erodium chrysanthum

E. chrysanthum has the best foliage I've seen in this genus, a brilliant silver of the sort people usually resort to annuals like dusty miller to get (though it doesn't show up well in this photo...), on a tidy compact plant that stays under 6 inches tall and slowly spreads to a foot or more in width.

Erodium chrysanthum

 The flowers look white in this photo, but are actually a delicate shade of the palest possible yellow. They're beautiful and produced continuously during the summer, but in all honesty are best described as sparse. This plant is all about the foliage, and the flowers are just a sprinkling of extra goodness.

Erodium carvifolium

Erodium circutarium

Erodium mannescovii

E. carvifolium, E. cirvutarium, and E. mannescovii look so similar that at first I wondered if they were different plants at all... but comparing the three side-by-side, they are distinct, and in the garden their growth habits are noticably different as well. 

All have large, dark green very ferny leaves that form an almost flat mat, only a few inches tall, but one year in, are already over a foot across, and all three are intense when it comes to flower production, blooming heavily all summer long with big masses of brilliant see-them-on-the-other-side-of-the-garden magenta flowers. 

Erodium carvifolium

I'm not usually a magenta fan, but these I like. A lot. They are loud and unabashed and cheerful. Comparing the three in the trial bed, my clear favorite is E. carvifolium Bigger leaves and flowers than the other two, it is also clearly the most vigorous and heathy of the three, and is blooming the heaviest. I do however also like E. circutarium, which holds its flowers more upright than the other two.

I did also put two other species of Erodium in the trial beds, E. chamaedryoides and E. richardii, neither of which made it through the winter... which came as no surprise. If you live somewhere warmer (zone 7 maybe 6) they're well worth growing, tiny, cute, adorable little things. But I think I'll stick with the hardy ones.

Exploring Erodium

I'm getting all geeked about the genus Erodium. Previously, I'd never really thought much about them, I'd sort of mentally classified them as being basically like Pelargonium, and assumed they wouldn't survive the winter.

How much I had to learn.

 First I noticed this incredible flower on E. cheilanthifolium and fell a little bit in love.

Then I saw this massive patch of Erodium chrysanthum's gorgeous silver, ferny foliage in one of the rock gardens here at Arrowhead and realized, wait... at least some of these things are hardy!

And with that, a new love affair had begun. I'm still a novice Erodio-phile, so please chime in if you know more about any of these, or know other species that I should be growing!

Firstly, since you just saw the foliage, these are the flowers of E. chrysanthum. Yum. The palest, palest possible yellow. It gives a sprinkling of flowers in the spring, and follows it up with another one now-and-again throughout the summer. Though frankly, with that foliage, who needs flowers? Totally hardy at Arrowhead.

Almost all the erodiums, like this wee little baby E. glandulosum I just planted in the Arrowhead trial garden, have a distinctive growth habit, with a tidy little mass of leaves at the base, and then then flowers dancing gracefully at the end of long stems well above the leaves. I absolutely love the look, especially since the flowers move gracefully with the slightest breeze. It is, however, devilishly hard to photograph. So I resorted to pulling bits off the plants and laying them on the ground.

Here's E. glandulosum (left) and E. cheilanthifolium (right) I love both of them very very much. Chelianthifolium's coloring is a bit more dramatic, but is reportedly only hardy to zone 6, while E. glandulosum is supposed to be hardy all the way to zone 4. I'm really hoping that zone 6 is an underestimate. I've planted some outside, and we'll see if I can prove them to be hardy here in zone 5. Both of these are good bloomers, with a heavy flush in the spring, and periodic flowering throughout the summer.

This is the hot pink trio I am having trouble telling apart. From left to right, E. maniscovii, E. circutarium, and E. carvifolium. Though each species has slightly different flowers and foliage, the over-all effect is the same. Ferny leaves topped with a constant supply of vivid magenta flowers. E. maniscovii and E. carvifolium are both reported as only hardy to zone 6, though the big plants of E. maniscovii in the garden here at Arrowhead tells another at-least-zone-5-hardy story. E. circutarium is supposed to be an annual... which makes me think that what we have as that at Arrowhead must be something else altogether, because out plants are certainly several years old. I appreciate the steady flowering of these species, but I don't love them... a bit coarse and ill-bred. And magenta. Not my favorite color.

So how about a big dose of cuteness? E. chamaedryoides 'Charm' is perhaps the more adorable little plant in the history of the universe. 

Little teeny-tiny baby pink flowers dancing just above a perfect tight little mound of dense green foliage. 

The double form, 'Flora Plena' is nice too, but nice quite as graceful. The plants in these photos are from the production greenhouses at Arrowhead, and you could literally walk in any day since March and see plants looking exactly like that. Hot, dry, cold, wet, nothing seems to phase them, they just keep on blooming.The bad news? They're not quite as hardy as the rest. Not reliable here in zone 5 Michigan, though they'll come through a mild winter or in a nice sheltered, well-drained spot. I think I'm going to try to overwinter some inside on the windowsill this year as well. They are so tiny and easy going it shouldn't be hard, and it is hard to imagine a houseplant that could lift the winter doldrums more than these little nuggets.

So. That's everything I know about my latest plant crush. What do you think? Any favorites you love that I'm missing?