Most gardeners are first introduced to the mallow family, Malvacea, through hollyhocks, old-fashioned flowers equally at home against a barn wall or suburban fence, in narrow city lanes or spacious country gardens. But plants as diverse as tropical hibiscus, shrubby rose of Sharon and common mallow (Malva neglecta), a pesky weed known to some as "cheeses", are relatives of hollyhocks. What do they have in common?
Family resemblance is most obvious in the flower form: the majority of mallows are more or less funnel-shaped, with five overlapping, heart-shaped petals flaring out from a prominent pistil. Also distinctive is the column of bushy stamens, like a little brush. In many mallows, fine veins of contrasting colour radiating from a central five-point star guides bees to their pollen-laden goal. Once you make the visual connection, you may recognize other members of the Malvacea family – hollyhock cousins, so to speak.
Learning to recognize common characteristics – flower form, leaf shape and arrangement, the profile of stems – that link one plant to another on the family tree can be a fruitful exercise for gardeners. Call it horticultural genealogy. Practically speaking, if one family member thrives in your garden, its relatives likely will, too.
I first saw musk mallows (Malva moschata, Zone 3) at the edge of our gravel country road and on the other side of a moss-covered, split-rail fence in a tangle of brier roses and half-wild apple trees that had grown up around an old, abandoned farmhouse. Somehow they stood out from other wildflowers – a bit fancier. Later I learned this mallow has always been considered an ornamental in its native Europe. Seeds were carried to this side of the Atlantic by early settlers as a reminder of gardens left behind. The enterprising plant soon set about colonizing fields and roadsides throughout Canada and the northern U.S. They have now come full circle, as roadside musk mallows leap back into cultivation. In our garden, we planted them deliberately in our flower beds and vegetable rows; now they pop up every year. We usually let them stay.
The musk mallow bears satiny, funnel-shaped flowers tinted soft mauve – mauve is French for "mallow" – or white. Starter plants give quick results; seeds are a slower but sure way to bring this easy-care, 60-centimetre perennial into the garden. Start seeds indoors or simply sow them where you want them in spring. Plants may bloom the first year or take a season to size up; a mature specimen presents a pleasing, space-filling shape in the mid-section of a bed.
Self-supporting musk mallows flower all through July and August, a pretty counterpoint to sea holly, phlox, purple coneflowers and monkshood. Rustic or refined, depending on their setting, musk mallows are elegant enough for formal beds but tough enough to naturalize in rougher parts of the garden.
Although perennial, they are not especially long-lived; in any case, younger plants give the best display. We let them seed at will and root out any that are out of place. Anyone who has grown hollyhocks will recognize the family's strength and weakness: many mallows seed vigorously, but few (except for roses of Sharon and shrubs) live beyond their third or fourth winter.
Hollyhocks (Alcea rosea) would likely be in more gardens if it weren't for two serious flaws. First, the plants are not long-lived; and (maybe worse) their leaves are susceptible to hollyhock rust, a disfiguring fungus that starts out as orange pimples and quickly spreads. Malva, Lavatera and Sidalcea spp. are also susceptible to rust. Younger plants are less prone to attack, so the best prevention may be to root out hollyhocks after their second summer -- by then they are usually rotting at the crowns anyway. Our method of rust control is simplicity itself -- as leaves shrivel, we cut them off. No sprays, no fuss. Often that means removing every last leaf. But, surprisingly, hollyhocks look better flying their colours without foliage than with a bunch of crumpled brown rags hanging from their stalks. Growing hollyhocks behind perennials that sport good foliage helps hide their lanky, bare limbs. Which leads to a third problem: hollyhocks like to pick their own location, coming up from seed in odd, unlikely places. Still, there's nothing as tall or colourful as hollyhocks in summer, nothing as old-fashioned and ordinary.