Tuesday, May 19, 2009

Try Brunnera in Dry Shade by Dusty M

Last year I attended a garden center class focusing on perennials for shady areas. I’m always looking for something that tolerates dry shade. I care for a family member’s yard filled with trees that cut off most sunlight except early and late in the day. The soil seems always dry, despite a thick layer of wood chip mulch plus the pine needles and leaves that collect there naturally. Tree roots suck up all the moisture in the soil. Grass stopped growing there some years ago. A little ivy has crept into the area, and there are a couple of other plants I’ll mention below. I place pots of shade annuals there in the summer. Fibrous begonias, impatiens, coleus, caladiums, and elephant ears do fine with daily watering.

At the end of the class I decided to try two possibilities. One was Paxistima canbyi (mountain lover), a low-growing spreading evergreen shrub that could provide some winter color, and Brunnera macrophylla ‘Jack Frost’ (Siberian forget-me-not), with blue spring flowers and silvery-patterned leaves for spring, summer, and fall. I planted the Brunnera at the edge of the grouping of annuals in their pots, which surround the trunk of a large old apple tree. It was watered daily along with the annuals through the summer but was neglected after frost and the annuals died away.

I was a little surprised a couple weeks ago when I noticed a hazy blue splotch near the apple tree trunk. I remembered the Brunnera and felt guilty forgetting it for half a year. I promised to do better next winter.

The Paxistima did not survive. Neither has bishop’s weed (Aegopodium podagraria), which I’ve tried in the past. In sunlight and more favorable conditions, it’s considered a pest that’s hard to control.

Others that do grow in this dry shade: Mahonia repens (creeping Oregon grapeholly) volunteers have moved in from a nearby foundation planting. An Agastache foeniculum (anise hyssop) plant has survived five or six years, after putting roots into the ground from one of the pots. (That’s a survivor!) This is not the popular xeric agastache that hummingbirds like. It’s a more compact anise-scented perennial with dark green leaves and blue/purple flowers, generally considered a plant for full sun and ample moisture.

(For more details about the Mahonia, see “Evergreen Shrubs for Home Grounds” at http://www.ext.colostate.edu/pubs/garden/07414.html and “Native Shrubs for Colo Landscapes” at http://www.ext.colostate.edu/pubs/garden/07422.html Paximista is among perennials and shrubs cited in “Ground Cover Plants” at http://www.ext.colostate.edu/pubs/garden/07400.html