Plants that thrive in the shadows: Conquering the challenges of dry shade gardening

Photo: Contributed

A shade-loving, drought-tolerant perennial to be offered at the OXA spring plant sale is this dramatic Aralia cordata 'Sun King' (Japanese spikenard).

Finding plants that thrive in dry shade is one of gardening's most formidable challenges.

These difficult spots are often located beneath mature trees or along north-facing walls or fences and present a double handicap. Not only do these areas receive minimal sunlight but plants must often compete for precious moisture. Yet, with careful selection of adaptable plants, even these challenging areas can become garden highlights.

The difficulties of dry shade gardening start with photosynthesis itself. Plants need light to manufacture food, and those receiving less must adapt their growth patterns accordingly. Many shade-loving plants evolved in woodland settings with naturally moist soil that offsets reduced light. But in dry shade, plants face not only minimal sunlight but also fierce root competition from established trees and shrubs that greedily siphon available moisture.

Beneath trees the dense canopy above may prevent rainfall from reaching the ground, while established root systems quickly absorb what little moisture does arrive. The resulting environment challenges even experienced gardeners.

Successful dry shade gardening requires both proper preparation and careful plant selection

Amending your soil with organic matter improves moisture retention and soil structure. Regular mulching helps maintain moisture levels, while occasional deep watering during establishment gives plants their best chance at success.

Included in our upcoming Okanagan Xeriscape Association spring plant sale will be three remarkable cultivars, which have proven their worth in conquering these difficult conditions. Each brings unique attributes that allow them to not merely survive but flourish where others fail.

Polemonium pulcherrimum “Golden Feathers” (Jacob’s ladder) stands out with its striking foliage featuring finely divided, ferny leaves in brilliant variegated gold that brighten even the darkest corners. This cultivar reaches a modest eight to 10 inches tall, with a width up to 14 inches, making it perfect for edging or in container plantings.

In late spring, delicate purple flowers rise above the foliage, creating a stunning contrast with the golden leaves. Polemonium “Golden Feathers” is hardy in Zones 5 to 9.

What makes “Golden Feathers” exceptional for dry shade is its remarkable drought tolerance once established, combined with a preference for partial to full shade. Unlike many golden-leaved plants that scorch in direct sunlight, it maintains its vibrant colour without fading throughout the growing season.

The herbaceous perennial Heuchera sanguinea “Snow Angel” (Coral bells or Alumroot) offers season-round interest. Its heart-shaped foliage with light green leaves is dramatically speckled with creamy white variegation.

This Heuchera variety forms an attractive mound, approximately 12 inches tall and wide and is zonally appropriate for planting in the Okanagan.

In early summer, slender stems rise above the foliage, carrying delicate pink bell-shaped flowers that are favoured by hummingbirds but seldom nibbled by deer. The flowers of Heuchera “Snow Angel” make an interesting cut flower with a long vase life.

“Snow Angel” succeeds in dry shade thanks to its adaptable nature and shallow root system that can capture surface moisture before it evaporates. The thick, leathery leaves reduce transpiration, conserving precious water reserves during drought periods. This cultivar demonstrates reliable drought tolerance once established and thrives in a wide range of soils.

Perhaps most impressive is Aralia cordata “Sun King” (Japanese spikenard), a bold architectural plant that brings tropical drama to shaded areas. This Japanese spikenard cultivar features compound leaves in luminous gold that seem to glow in dim light.

Growing four or more feet tall and wide, it creates dramatic structure and should be located in the middle or back of your shade border. In middle to late summer, tiny white blooms appear, followed by dark purple inedible berries.

The flowers of Aralia “Sun King” are attractive to bees and other pollinators with the foliage unappealing to deer. “Sun King” was awarded 2020 Perennial Plant of the Year by the Perennial Plant Association.

“Sun King” conquers dry shade through several adaptations. Its extensive root system can access deeper water sources beyond the reach of competitors and the large leaves efficiently capture available light.

Despite its tropical appearance, this perennial demonstrates surprising drought tolerance once established, requiring only occasional supplemental watering when grown in a shady location.

These three exceptional cultivars demonstrate that dry shade locations needn't remain a garden wasteland. With thoughtful plant selection and proper care during establishment, even these challenging areas can be transformed into vibrant, textured spaces that contribute to the garden's overall beauty.

By embracing these adapted plants, gardeners can convert previously problematic areas into new opportunities for creative expression.

Visit our plant database on our website at okanaganxeriscape.org for information about other species that flourish in areas of dry shade.

•••

• As in years past, OXA will represent the Make Water Work campaign at nurseries throughout the Okanagan Valley and will be onsite to answer any of your gardening and xeriscaping questions.

• Mark your calendar for OXA’s plant sale on May 10 from 10 a.m. to 3 p.m., at 840 Old Vernon Road. We will be having a member-only pre-sale on Friday, so consider becoming a member for this and other valuable benefits outlined on our website.

• The Okanagan Xeriscape Association is grateful for the ongoing financial support of the Okanagan Basin Water Board and is proud to be collaborating on the Make Water Work campaign. Check out the Make Water Work plant list at makewaterwork.ca.

Sigrie Kendrick is a master gardener and executive-director of the Okanagan Xeriscape Association.

This article is written by or on behalf of an outsourced columnist and does not necessarily reflect the views of Castanet.