Woodland-Style Shade Gardening

Gardening Newsletter Vol. 7, Issue 4 - July 2012

The author’s woodland garden displays a range of attractive plants.

Designing a Woodland Garden The woodland garden has a distinctive character. For many, it instills a sense of serenity and relaxation. While peaceful, it is not without action and animation, as many birds, insects and other creatures make their home here. Some may consider this type of garden to be somewhat messy looking, but pinecones, acorns, leaves, broken branches and twigs strewn about the ground are nature’s litter and add realism to the design. The diversity of plant life, from groundcover to knee-high wildflowers to shoulder-height shrubs to towering trees, creates a layered look. The garden’s line and form is often composed of interconnected capes and bays that mimic the shadow cast by overhead trees. This meandering outline draws the eye in and releases it outward; it also establishes repetition and rhythm, two important elements in garden design. Before proceeding with your garden plan, evaluate how shady your garden is, how long the shade lasts and its sources. Tall buildings will cast a shade quite different from that of the foliage of open-branched trees. The selection and placement of plant material will depend on this evaluation, as well as a number of other factors such as plant form, texture, summer interest, fall colors and fruits. Additionally, tree and shrub silhouettes are critical for adding winter interest. 1/5

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Woodland-Style Shade Gardening

Gardening Newsletter Vol. 7, Issue 4 - July 2012

When it comes to woodland flowers, remember that they are often short lived, disappearing when overhead tree foliage appears. As well, many woodland plants produce soft, pastel-colored blooms that make a statement only when planted in large quantities. The distribution of plants, particularly wildflowers, should be somewhat informal and respectful of their natural growth patterns. Photographs of local parks and conservation areas will give you valuable insight as to how they should be sited. Where I live (Canadian hardiness zone 6; American zone 5), trilliums grow in clumps, rhizome-rooted Solomon’s seal (Polygonatum biflorum) grows in drifts, stolon-spreading foamflower (Tiarella cordifolia) forms sheets, and seed-spreading native columbine (Aquilegia canadensis) appears at random. Groups of plants in a woodland garden tend to weave into each other, with their edges often overlapping. Taller trees dominate the upper levels, while smaller horizontal-branched trees, such as the alternate-leaf dogwood (Cornus alternifolia), with its pagoda-like shape, and redbuds (Cercis canadensis), reach for light at lower levels.

Woodland plant life: white trillium (foreground), which turns pink as it matures; foamflower (white spiky flower in foreground); lady’s slipper orchid (amid trilliums); bluebell (back left corner); wood poppy (yellow flowers in background) and white bleeding hearts (right back corner). 2/5

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Woodland-Style Shade Gardening

Gardening Newsletter Vol. 7, Issue 4 - July 2012

Focal points are usually understated, and often can be likened to “nature’s recycling”. Consider a moss-covered log, a fungi-encrusted stump, a twig arbor or a rustic log bench. Unusual and aesthetically appealing plants, such as Jack-in-the-pulpit and multi-petal trilliums and bloodroots, can also serve as focal points. Don’t make them obvious, though; instead, make the viewer search the depths of the garden for these treasures. While woodland gardens may be somewhat slow to become established, they are nonetheless dynamic, changeable landscapes where some plants are more successful than others due to root competition and changing light, soil and moisture conditions. This adds to the garden’s diversity and interest, and gives gardeners a chance to try cultivating different plants over time. Some Challenges In my woodland garden, I struggled with the role of non-native, shade-tolerant species. When I started the landscape some 35 years ago, I was a nativeplant purist. Accordingly, my garden was resplendent with hepatica, wild ginger (Asarum canadense), trilliums, Solomon’s seal, woodland phlox and various ferns. Over the years, I found this somewhat limiting and wanted more flower and foliage color, particularly in the summer. I made room for some showy non-natives, while still allowing the natives to dominate. However, I was careful to avoid non-native quick spreaders such as Japanese spurge (Pachysandra terminalis), vinca and various ivies.

Alpine columbine (foreground), alpine lady’s mantle (to right of columbine) and phlox (light purple flowers in background) in the author’s garden.

3/5

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Woodland-Style Shade Gardening

Gardening Newsletter Vol. 7, Issue 4 - July 2012

The first group of non-native plants I incorporated included showy, variegated foliage plants such as variegated lungworts (Pulmonaria spp.), variegated brunneras, Japanese painted fern (Athyrium niponicum var. pictum), Japanese forest grass (Hakonechloa macra ‘Aureola’), variegated Solomon’s seal and some variegated hostas, including Hosta ‘Patriot’ and others. Several years later, to add some summer flower color, I planted Jacob’s ladder (Polemonium caeruleum), masterwort (Astrantia major), heartleaf bergenias (Bergenia cordifolia), lady’s mantle (Alchemilla mollis), bleeding heart (Dicentra spectabilis) and martagon lily (Lilium martagon). I used goat’s beard (Aruncus dioicus), with its showy white flower spikes and lacy foliage, to hide my compost mixingand-storage area at the rear of the garden. Its inclusion pleased my eyes and expanded my knowledge and interest in a broader palette of plants. Another challenge was the matter of fall interest. To me, autumn is not an off or shoulder season for the woodland garden, but rather prime time for beautiful colors and fruits. Trees such as the eastern flowering dogwood (Cornus florida), with its striking purple-red foliage, turbanshaped flower buds and remarkable red fruits, accompanied by the buttery-yellow foliage of red buds and the red, yellow and orange of bottlebrush shrubs (Fothergilla spp.) were magic. Fall flower color was introduced by black cohosh (Actea racemosa), with its white wand-like flower spikes, native witch hazel (Hamamelis virginiana), with its curly yellow ribbon-like blooms, and the spectacular perennial toad lilies (Tricyrtis hirta). Shade falls over the flourishing plant life in this woodland garden. 4/5

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Woodland-Style Shade Gardening

Gardening Newsletter Vol. 7, Issue 4 - July 2012

Maintenance Of course, woodland gardens are not maintenance free. As my canopy trees matured, ground-level wildflowers started to thin out. Removing the lower limbs (up to 10’, in my case) and pruning overgrown shrubs allowed more light to reach the ground and rejuvenated existing plants. I found some newly planted wildflowers and non-native shade species were being thrust out of the ground after alternate freezing and thawing during winter. I carefully reinserted them at their proper root depth and applied mulch. An annual application of a couple of inches of mulch (I use a finely ground pine bark mixed with compost) adds nutrients to the soil and helps condition and insulate it. It does not smother my plants, as roots adjust by growing up into it. My woodland plants have proved fairly disease resistant, as a number, such as the native ferns, contain alkaloids that deter insects. Slugs and snails can make their presence known by creating holes in ground-hugging foliage. Approved slug and snail baits, copper strips, crushed eggshells and even beer can be part of the gardener’s arsenal against these invaders. I occasionally had some problems with mildew but found that fostering good air circulation through plant placement and pruning helped to prevent it. Lastly, I keep a watchful eye out for plants that could seed and take over the garden. For me, these include dame’s rocket (Hesperis matronalis), garlic mustard (Alliaria officinalis) and various violets (Viola spp.). In conclusion, go with the shade and try a woodland garden. You will come to love these very special plants and the look they impart. Text by Frank Kershaw Photos by Marilyn Cornwell Frank Kershaw is an award-winning horticulturist with 35 years’ experience. He teaches garden design and horticultural courses at George Brown College in Toronto, Ontario, and at the Toronto Botanical Garden. Frank is also a presenter at the Lee Valley Tool Ltd. seminars at the Toronto stores. Photographer Marilyn Cornwell lives and gardens in Toronto, Ontario. Her website is marilyncornwell.com. 5/5

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