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 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.
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.
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.
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.
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.
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.