the toughest groundcovers i rely on

Geranium macrorrhizum, the big-root geranium: I wonder how many square miles of this plant I have grown. The bigroot geranium is so named because instead of a clumping habit, it grows from a ropelike rhizome that seems to barely need to touch the ground to thrive. Its attractive foliage has an aromatic, spicy scent, and is nearly evergreen even in my Zone 5B garden.
It will survive, I think, except in the wet; sun or shade, and even dry shade. All I give it is an annual haircut, and I do that when spring is turning to summer, the flowers have gone by and the leaves are stretching upward. Deadheading would be another option, but just shearing the whole plant is faster in masses, and also keeps it tighter and denser.
The straight species is pink (but not pastel); if Pepto Bismol isn’t going to work for you, there is the more prim ‘Ingwersen’s Variety,’ with nearly white blooms (and a less rampant overall demeanor, too, I think).

Shady locations suit epimediums, and once established they can really take it dry. In fact, their woody rhizomes will resent a wet spot, and rot. Like many woodlanders with these woody underground parts, I find they like an intervention every now and again: When a clump gets really full, I go in and divide it, and repeat my success elsewhere with the divisions.
Plan to cut back their nearly evergreen foliage in late winter, as we have discussed before.
I highly recommend calling or writing for a catalog from Garden Vision, now owned by Karen Perkins, who has worked with Darrell since the operation’s founding in 1997. A website is in the works, but for now: (978) 249-3863 or email to epimediums at earthlink dot net.


Do you have areas where a one of these would help thwart weeds, shade the soil, and just tie things together visually? Or do you have any other reliable great groundcovers to recommend?

Love macrorhizum. I saw your stands at a garden open day, Margaret, last year. Very impressive. I have 1.5 acres in the Hudson Valley; seed bank is the devil here. GM is a trooper under three of my oaks. It’s growing much better than the Christmas ferns which share the same space but I think the ferns just need more time to grow to the full size. Lots of weeds here. I just sheared the GM today, and there was not a single weed under it. I am looking for the “white ness“ cultivar to transition better with my autumn ferns (copper orange spring foliage clashes with the magenta flowers of Bevans); and fingers crossed they are just as tough. My husband wants me to plant this on all the edges so he doesn’t have to weed wack.
Margaret,
I must tell you! Years ago I took a tour of your garden- it may even have been before your column started- and you gave out pieces of your geranium. Here in Brooklyn, mine is still here, thriving in dry shade! The pale pink flowers, out now, I like to pair with greenish-white tulips from the supermarket, and it makes a very pretty bouquet!
I’m trying to find a ground cover to put in a narrow space between two driveways. Because I live in Wisconsin, this area will get some salt on it during the winter as we try to melt ice on our driveway. This area also has poor soil and gets full sun.