The Friends of the Wild Flower Garden
by Gary Bebeau
Dogwoods add a rich texture to the landscape - from the showy flower clusters of late Spring, to the colorful fruit of Summer, to the leaf color of Autumn, and the variety of bark color year around.
Six Dogwoods are considered native to Minnesota and five are indigenous to the Wildflower Garden - Bunchberry, Red osier, Gray, Pagoda, and Round-leaf. The missing one, Silky (or Pale), was added in 1913. (1) Five are shrubs and one is herbaceous and perhaps less seen as it is an acidic bog dweller -Cornus canadensis - the Bunchberry - and it alone has showy white bracts and inconspicuous flowers that produce red fruit. Four of the six remain in the Garden - Roundleaf and Bunchberry having gone missing.
Eloise Butler considered then all to be bog trotters (2) but today one is more likely to find a few of them in a variety of habitats. Except for the Bunchberry, which is herbaceous, they grow as shrubs. The flowers of the shrubs all have 4 spreading white petals and are in clusters at the end of twigs. Leaves are usually longer than wide without teeth. Eloise Butler remarked that “The dogwoods richly furnish forth the bird tables” (2) and it is by the fruits yea shall know them - but only during a short period until the birds eat them all. Fortunately identification is not impossible, so here is a short-course.
Preferring marshes and other moist areas with sun are Red osier (C. sericea) and Silky (or Pale (C. obliqua). Both flower clusters look similar as do the leaves but only Red-osier has reddish bark with white spots (lenticels) in all but summertime and the leaves are deep purplish red in autumn. Silky has purplish bark with reddish undertones. Red-osier’s drupes are leadish-white with pale red stalks; Silky has dark blue drupes with unexceptional stalks.
The Roundleaf (C. rugosa) likes moisture but with shade. The leaf is - yes - roundish, the stem is greenish, and the fruit is light blue on pale red stalks.
Tolerating both shade and sun, moist soils and slightly drier soils is the Pagoda (C. alternifolia) which is the only one of these dogwoods that can grow as a small tree instead of a multi-stemmed shrub. If you plant one, it will try to be a multi-stemmed shrub, but thinning the suckers when young will produce a small tree.
Willing to leave the bogs and marshes without regret is the Gray Dogwood (C. racemosa). It will handle drier upland type soils and likes sun - so much so that former Gardener Cary George considered it a “one of the woody plants that plague the prairie garden”.(3) Again, the names tell the story - the bark is gray and flower cluster is more elongated, like a raceme as the species name, racemosa, tells us. The fruit is a nice white on red stalks and when set off against the purplish-red autumn leaves - it is quite a sight!
For a home landscape, many nursery cultivars of Red osier are available and even the native species does well with adequate moisture. I have seen Pagoda growing as a 20 foot high tree. The photo below is of that tree.
Photos are by G D Bebeau unless otherwise credited.
Below: Pagoda Dogwood showing its large flat-topped flower clusters and tufts of glossy leaves.