When most people think of China in a context of color, after the obvious Chinese Red hue, they think of the traditional gardens with their serene green palette or of the intensely colorful temporary pot gardens that bloom along steps, driveways and hotel lobbies. On our last trip to China; however, I discovered that they have developed a new passion: a passion for purple. It is used now for foliage color in contemporary plantings and highway medians, or as floral color in beds and hedges. For our home gardens here, there is a broad palette of purples and Julie and I have picked a few to recommend for your garden.
GORGEOUS GROUND COVERS
We have many choices for purple ground covers. Liriope ‘Royal Purple,’ a 2011 Plant of Merit, has stunning, deep purple flowers and lush foliage. The number of Heuchera hybrids continues to expand with a multitude of fancy-leaved forms in shades of honey rose with chartreuse to deepest purple-black. The cultivar ‘Amethyst Mist’ has deep purple foliage with silver spangles and ruffled edges and will delight in our shady, limestone- rich Missouri gardens.
For another great group of purple-leaved ground covers, try the ajugas. A. pyramidalis ‘Metallica Crispa Purpurea,’ is a great claret and lavender ground cover as the dark leaves set off the lighter flowers with nice contrast. Ajuga reptans cultivars ‘Black Scallop,’ ‘Burgundy Glow’ and ‘Mahogany’ all have dark purple foliage with subtle variations. ‘Chocolate Chip’ is a miniature version with dark leaves and ‘Golden Glow’ has a gold and green variegated leaf with streaks of purple. All ajugas need excellent drainage in this area to prevent crown rot, and a little afternoon shade doesn’t hurt, either. Put them inside the fence if you have deer.
TREES AND SHRUBS
Many trees and shrubs offer colorful purple to bronze foliage, including crimson barberry, copper beech, Japanese maple, and some of the crab apples. The most traditional purple-leaf plum can be enjoyed in the Plum Viewing Arbor of the Japanese Garden, with soft orchid-pink blossoms in the spring and deep maroon foliage well into autumn. ‘Newport Purpleleaf’ is a strong performing purple foliage plum commonly available in the market. Acer palmatum ‘Purple Ghost’ is an aptly named cultivar of Japanese maple.
The classic plant that gives a name to the mainstay shade of purple is the lilac. Most lilacs suffer from borers and powdery mildew when grown in St. Louis, but the Korean lilac, Syringa meyeri ‘Palibin,’ is a dwarf cultivar that offers mildew resistance and rates five stars. Syringa pubescens subsp. patula ‘Miss Kim,’ a cultivar of the Manchurian lilac, also is a reliable performer for our Missouri gardens.
Another favorite purple-flowered shrub is the hybrid crape myrtle Lagerstroemia. Fifty years ago, U.S. National Arboretum (USNA) plant breeder Don Egolf started hybridizing the southern indicas (not winter hardy for us) with L. fauriei stock collected in Japan by Dave Creech. The fauriei parentage brought a host of wonderful qualities, including mildew resistance, cinnamoncolored exfoliating bark and better winter hardiness. With this breeding program and our local climate shift of the last few decades, we may now grow crape myrtles with more reliability. Yes, in some brutal winters we may get top kill and have to start over from the soil line, but these shrubs and small trees stand up extremely well to our intense summer heat and yield the best big color for our August and September gardens.
The series started out as the “Ten Little Indians,” but the National Arboretum has now patented some 30 crape myrtle releases, two-thirds of them with L. indica x L. fauriei parentage. They are top-hardy to Zone 7 and root hardy for us in Zone 6. Plant them where they receive some winter protection and prune to live wood each spring just after they start to break bud. Discouraging tender late-season growth and mulching well will help increase their winter survival. There are many specimens in the city that have reached (and maintained) heights of 20 feet or more. Wide ranging in form, the dwarf ones may be used for mass planting in large islands, loose informal summer hedges or as potted terrace plants. Taller varieties are best trained as multistemmed street trees and are an excellent scale for use in patio or terrace landscapes. The four-season interest adds to their value, with textured bark, long bloom season and remarkable fall color.