SIDALCEA: Checker Mallow
One of the loveliest of our native wildflowers has got to be Sidalcea, or checker mallow. It is truly a cheery sight in late spring through early summer, the tall stems of delicate hollyhock-like blossoms of white to rosy pink standing tall in the sunny border of the garden, actively visited by both bees and butterflies.
Of the two dozen or so species of Sidalcea native to western North America, about ten are native to Oregon. There are species that make their home along the coast and on each side of the Cascades, so there are checker-mallows suitable for a range of garden conditions. For the most part, they are best in a full sun to partial shade location. Most are also happiest with moist to wet, well-drained soil (some will tolerate hotter/drier conditions too, if they're given a bit more shade, or extra attention with supplemental watering).
They are all very similar in appearance: basal rosettes of rounded, gently lobed leaves, with the leaves growing along the flowering stems markedly more dissected. At the tops of the flowering stems are clustered spikes of white to pink to red-rose flowers with tiny malva/hollyhock like blossoms. The task is to select the one best suited to your particular garden.
About the only real deal buster with these plants (and not enough not to grow them, I don't think) is that they can become afflicted with rust and leaf spot if grown in too wet conditions with insufficient air circulation (they are prairie/meadow plants mostly, so think more open space). A little care can prevent the worst of this from happening, and the rewards are abundant.
Bees and butterflies will enjoy your Sidalcea; some species are beneficial as host plants for the caterpillars of a few of our native butterflies, an added plus. To have enough for you and for the caterpillars to enjoy, they are fairly easy to propagate from seed (see side bar).
Here's a selection of Sidalceas:
S. campestris – meadow checker mallow
Possibly the most versatile checker mallow for the garden. Blooms late spring to early summer. Flowers white with light pink to pink.
Prefers full sun to light shade, and well-drained moist to rather dry soil (give more water in hotter/drier areas).
Grows 2-6 feet. Easily propagated by seed.
S. cusickii – Cusick's checker mallow
Found only in open, riparian sites in western Oregon. Rose-pink petals deepen in color as they age. Grows to 5 feet.
Thrives in full sun to partial shade and consistent watering. A particular favorite of butterflies.
S. hendersonii – Henderson's checker mallow
Inhabits tidal marshes and wet coastal meadows. However, can be successfully grown in gardens on both sides of the Cascades.
Beautiful addition to a moist/wet wildflower garden. Red purple flowers top out at about 5 feet.
Photo Credit to Dana Visalli.
S. hirtipes - bristly-stemmed checker mallow
This Sidalcea makes large, spreading clumps from short rhizomes in moist, open meadows and bluffs in the coast range.
Will grow in both full sun to partial shade with plenty of water. Rosy-pink flowers grow to about 3 feet.
Photo credit to Phil Slichter.
S. malviflora – dwarf checker mallow
Growing no more than 2 feet, with flowers ranging from pale to deep pink. This is a varied species, containing 13 subspecies, half of which can be found throughout western Oregon.
In the garden, give it full sun to part shade and regular water.
S. oregana - Oregon checker mallow
One of the Sidalceas from east of the Cascades. Found in moist meadows but also in and around dry forest areas. Light to dark pink flowers, grows 2-4 feet in height. This is the one that can reliably grow in drier conditions.
Another for summer dry gardens from the far north-eastern and south-eastern counties of Oregon is S neomexicana, but it is uncommon and rarely available.
Common Name: checker mallow
Origin: Western North America
Characteristics: Basel clumps of lobed leaves, with those on the flowering stems often more finely dissected. Flowers are in white to pink clusters at the top of the stems, resembling delicate hollyhocks.
Culture: Most checker mallows will grow well in full sun to partial shade, in moist to wet or sometimes drier conditions, depending on species.
Maintenance: Regular water and well-drained soil. Deadhead spent flowers to promote bloom. Cut plant back down to the basal rosette of leaves in the autumn.
Pests & Diseases: If grown in conditions too wet with too little air circulation, leaf-spot or rust can occur. Otherwise, does not seem to be especially bothered by any pests or diseases
Propagation: Native checker mallow can be grown from seed collected in the late summer or early fall, either sown directly in the garden or in flats that are left outside to chill for several weeks. Seeds will germinate in the following spring.