The thought of shade gardens calls to mind stalwarts such as hostas, ferns and astilbes. While the New York Botanical Garden’s Azalea Garden has an interesting array of exquisite hostas and intriguing ferns, it also includes less familiar woodland inhabitants.
Many of the plants described below have interesting foliage that adds texture and color to shade gardens. A number of these plants flower late in the season, providing color long after spring ephemerals and the majority of azaleas have finished their early season show. These woodlanders come in all shapes and sizes, from groundcovers to large perennials, and in a myriad of leaf colors and textures, from variegated, deeply veined, tinged and fuzzy to matte and glossy.
Mukdenia rossii ‘Karasuba’ is one of two unusual plants in the Azalea Garden whose foliage is tinged a beautiful red as the season progresses. A relative of the coral bell (Heuchera), it has been available for a few years with specialty growers and now is becoming more widely available. Mukdenia is native to Korea and China, where it grows on slopes and in rocky ravines at the side of streams. In the garden, it will perform best in moist, well-drained soil in part shade.
Mukdenia grows 12 to 16 inches tall and fans out 12 to 24 inches, like coral bells, into a nice clump. Panicles of small white flowers rise above the plant in early spring, similar in appearance to foam flowers (Tiarella). The main attraction of mukdenia is its foliage: spectacular, fan-shaped leaves that turn red around the edges in mid-summer and continue coloring into fall. The plant pairs nicely with late flowering red astilbe such as Astilbe x arendsii ‘August Light’.
Beesia deltophylla, a native of China, gets red hues as the summer progresses. It will grow in many soil types but does best in moist, well-drained soil in part to full shade; it grows 10 to 15 inches tall and spreads up to 24 inches wide.
Beesia makes a wonderful evergreen groundcover in a woodland garden when planted in drifts. The foliage is spectacular: The leaves are large, glossy and heart-shaped, with deep veins that give them a rippled, puckered appearance. Beesia looks like a mutant European ginger on steroids (in a good way). Small white flowers appear in summer on tall stems and are fairly insignificant compared with the foliage.
Syneilesis aconitifolia, the shredded umbrella plant, pokes its head out of the ground in spring wearing a fuzzy white coat that disappears as it matures. The leaves open like an umbrella to reveal large, heavily dissected, lacy leaves, looking like a mayapple (Podophyllum) that has passed through a paper shredder. The shredded umbrella plant will thrive in part to full shade and can tolerate relatively dry soil. It reaches two feet in height. Its dissected foliage looks great when paired with a broad-leaved hosta that has smooth or puckered foliage.
Aconitum krylovii, a monkshood from Russia, is among the woodlanders that are deer-resistant, or have the promise of being so. It can be grown in full sun to full shade and matures to a height of two feet. Its deep, green, deeply veined, maple-like foliage is attractive even when the plant is not in bloom. Its white to pale-yellow flowers tinged with green open mid- to late summer.
Both deer and rabbits tend to avoid members of the mint family and so may also pass up Leucosceptrum japonicum ‘Variegatum’ and Leucosceptrum stellipilum ‘Ogon’, Japanese shrub mints. The ‘Variegatum’ has brilliant chartreuse-and-green variegated foliage that brightens up any shade garden. ‘Ogon’ has yellow-green foliage that is equally as impressive. Both produce pale-mauve flowers late in the season, September to October, and reach 2 to 3 feet tall.
Rabdosia longituba, trumpet spurflower, also in the mint family, looks similar to many late season ornamental salvias. This relative has an open and airy, vase-shaped habit. It grows to 3 to 4 feet tall with long sprays of tubular, lavender flowers that appear from October into November. It thrives in average garden soil but will tolerate dry soils, does best in part shade and pairs nicely with Japanese anemone (Anemone japonica).
The Azalea Garden has some unusual members of the hydrangea family, all recognizable by their hydrangea-like foliage. Two are perennials that reach about 18 inches tall. Cardiandra alternifolia flowers in late summer with pretty pale-pink flowers reminiscent of a lace-cap hydrangea. Deinanthe caerulea ‘Blue Wonder’ flowers in midsummer with large, nodding, lavender flowers. It has the demeanor of a hellebore. Both these woodlanders like part shade and moderate to moist soil. The sub-shrub Platycrater arguta reaches 2 feet tall and 2 feet wide. It flowers in midsummer with white blooms that resemble mock orange (Philadelphus) or deutzia (Deutzia).
The azalea garden has many other interesting, exotic woodlanders to explore such as the late-blooming (September to frost), creamy-yellow flowered Salvia koyamae and the penstemon-like, purple-pink blooms of the Chelonopsis yagiharana (August into October). For early season color try the elegant, Asian twinleaf, Jeffersonia dubia, with its lavender, cup-shaped, flowers and lobed, red-edged foliage or the tough, weed-smothering Trachystemon orientalis, with its borage-blue spring flowers and large heart-shaped leaves.