Pachysandra as Evergreen Groundcover

One of my former neighbors persisted in trying to grow Pachysandra as a groundcover under his oak trees. Tray after tray of plugs arrived and were planted in spring, only to die by fall. He finally relinquished his preferred plan and planted variegated Bishop’s Weed (Aegopodium podagraria) instead. Also called Goutweed, Snow On The Mountain, or Ground Elder, Bishop’s Weed is an aggressive, invasive groundcover that is difficult to eradicate once established. I suggest you avoid it.  Given the neighbor’s difficulty in growing Pachysandra, imagine my surprise last year when I stumbled across a large (forty feet by seventy feet) patch of it growing on a woodland bank near my creek. In May, it looked like a large emerald blanket, and even draped over the creek bank like a curtain. This week, it shows the ravages of extreme cold and too much rain, but it is still an effective groundcover. I have no doubt that it will return to its former glory when temperatures warm in spring.

 There are two species of Pachysandra. Allegheny Spurge (Pachysandra procumbens, pronounced pak-ih-SAN-drah pro-KUM-benz) is native to the southeast. It is evergreen to semi-evergreen, and cold hardy in zones 7-8. It grows in rich, moist, acidic soil, in dappled shade to full shade. It is not invasive. This is the variety that is living happily in my woodlands. It averages nine inches tall and has not been browsed by deer, despite heavy populations in this area.

 Like other plants we have adopted from the Land of the Rising Sun, Japanese Pachysandra (Pachysandra terminalis, pronounced pak-ih-SAN-drah ter-min-AL-iss) tolerates a wide range of temperatures (zones 5b-9a) and is a more aggressive grower than the native type. It may grow up to a foot tall but is typically shorter, and spreads by underground rhizomes. ‘Green Sheen’ is especially heat tolerant. ‘Green Carpet’ is a mounded uniform form that lends itself to edging for shady beds.

 Both the above species bloom in spring, but the flowers are not particularly eye-catching. Bees love them. Pachysandra is in the same family as Boxwood and shares some of its susceptibility to scale, leaf spots, and root rot. Don’t overwater, and if dead or diseases patches become apparent, remove them before the problem spreads to the rest of the bed.

Big box stores usually sell Pachysandra in trays of 2-inch plugs. Tease them apart carefully to avoid damaging tender roots. Place plugs six inches apart for rapid coverage, or up to a foot apart. Even at the wider spacing, ground coverage should be complete in three years. when grown in moist shade and fertile soil. Be careful to avoid constantly wet soils.

New Ajugas, New Colors

It is freezing outside. The wind is moaning like a banshee with a hangover. And I am indoors, fireside, with a cat on my feet and a lap full of nursery catalogs. It’s always fun to see the year’s newest seed and plant introductions and to read all the descriptions. A catalog from a seed company in South Carolina. has a whopping 184 entries for tomatoes. How can growers find 184 different ways to describe a tomato? And yet, they do.

Among the new plants for 2021 is an entire series of Ajuga reptans. ‘Feathered Friends’ encompasses seven new cultivars with golden, bronze or almost-black leaves. My heart beat a little faster when I saw Ajuga ‘Noble Nightingale.’ Some interior decorators recommend a touch of black in each room. A touch of black or almost black can elevate a so-so container combination to wow. Black mondo grass (Ophiopogon planiscapus 'Nigrescens') has been my go-to plant for containers, but ‘Noble Nightingale’ is only four inches tall, with a spread up to 18 inches. I can envision it with Euphorbia ‘Diamond Frost’ and something pink — Begonias or Caladiums. ‘Cordial Canary’ has golden yellow foliage, unlike any other Ajuga. ‘Parrot Paradise’ has leaves with shades of yellow, orange and red. From a distance, it reads as bronze.

Ajuga (common name is Bugleweed or Carpetweed) is easily grown in partial sun or shade. It will tolerate some drought. Blue flowers are a bonus. These undemanding groundcovers spread quickly, giving rise to some gardeners’ assessment of the plant as invasive. (It is a member of the mint family). It will grow and even thrive in many situations where other plants, including grass, won’t grow such as deep shade, dry soil, or under Black Walnut trees. It will tolerate minor foot traffic. Plants can be so vigorous that congested areas die. Prevent this by division. Ajuga is resistant to damage from deer and rabbits. Other than dieback from congestions, their only problem is root-rot when placed in wet soils.

The Mary Snoddy garden features ‘Burgundy Glow’ and ‘Black Scallop’ but these new cultivars are alluring. The above-mentioned ‘Feathered Friends’ is offered exclusively by Mast Young Plants. Here is a link to their site, so you can see photos of these beautiful new foliage colors: Ajugas

This photo of Ajuga ‘Black Scallop’ was taken February 3, proving that this groundcover for shade can look as good in mid-winter as it does during the warmer months. The almost-black foliage looks wonderful when paired with chartreuse, such as Lysimachia aurea, “Creeping Jenny” or rose shades, such as a bronze-leaf wax begonia with pink flowers..

Ajuga ‘Burgundy Glow’ lights up a dark area.

A planting of Ajuga ‘Chocolate Chip’ along a walkway at Hatcher Garden and Woodland Preserve. (Photographer is unknown, unfortunately.) The shiny, rounded leaves offer beautiful contrast to the delicate fern fronds and the rough granite stones.

A new planting of ‘Black Scallop’ Ajuga pops against the chartreuse foliage of Talinum (“Jewels of Opar” and the rounded leaves of several Hostas. It will eventually spread to cover all the pine needle mulch.

This Broom Is Not For Witches

I profess an above average plant knowledge, so I was a bit embarrassed recently when a visitor to the Mary Snoddy grounds (she is a fantastic gardener) corrected my mis-identification of Butcher’s Broom as Poet’s Laurel. She was right!

Butcher’s Broom (Ruscus aculeatus) is in the same genetic family (Asparagaceae) as Poet’s Laurel (Danae racemosa), along with Cast Iron Plant (Aspidistra), Asparagus Fern, and Sacred Lily (Rohdea – a fabulous plant to be featured in a future blog). Broom and Laurel share unusual characteristics. What appears to be leaves are actually modified stems, known by botanists as cladophylls. Both have foliage that lasts a long time when cut, making them favorites among the flower arranging community, and both have beautiful orange-red fruits in fall. Butcher’s Broom, however, has thorns hidden along the stems that will snag an unsuspecting gardener. Poet’s Laurel does not have these prickles. Both the Broom and the Laurel enjoy dry shade to part shade, zones 7 to 9. They tolerate a wide range of soils and are drought tolerant once established. The Laurel has a weeping habit while the Broom is more upright. Butcher’s Broom may eventually reach three feet in height with a bit wider spread. Poet’s Laurel will mature at four feet in height. Any branches that die should be cut off at ground level.

Butcher’s Broom and Poet’s Laurel are difficult to propagate and slow-growing so when available in plant nurseries, they are likely to carry a healthy price-tag. Brooms normally need both female and male plants nearby in order to produce those marble-size fruits, but ‘Wheeler’s Variety’ will self-pollinate. Brooms spread (gradually) from a creeping rhizome. If you are patient, you can also push the seeds into soil but expect to wait three years or more before you see leaves.

Neither plant is bothered by diseases or browsed by deer. One easy way to remember the plants’ identities is to recall that Poet’s Laurel was once used to form crowns for victorious athletes (hence the phrase, “resting on one’s laurels”). With its needle-like thorns, Butcher’s Broom would make an uncomfortable tiara.

The rich green foliage looks fabulous when paired with variegated plants or lighter green foliage. In a new bed, I have planted it with an under-dressing of ‘Black Scallop’ Ajuga (purple) and chartreuse “Jewels of Opar” (Talinum paniculatum). Even without the orange-red berries of a mature Butcher’s Broom, this color combination pleases me and I think it will only get better with age, though I may need to provide supplemental water for the Ajuga.

"File:Butcher's Broom (Ruscus aculeatus) (15720512577).jpg" by Bernard DUPONT from FRANCE is licensed under CC BY-SA 2.0

Indian Pink, Beautiful Native

Indian Pink, also known as Pinkroot, is a native perennial wildflower. Its tubular flowers light up shady areas and attract hummingbirds. The Latin name, Spigelia marilandica (pronounced spy-GEEL-ee-ah mar-i-LAND-ih-kah) rolls off the tongue easily, with a musical quality that is absent in the common name. Spigelia is considered a threatened species in several states. I treasure my stand, and guard its good health. Plants are not widely found in nurseries. Mine came from a Native Plant Society sale.

Spigelia grows in light shade and prefers damp soil. It will survive periods of drought once established and will not tolerate a boggy area.  Keep the lime away from this one; it prefers an acidic-to-neutral home. Woodland soil high in organic content is ideal. Plants bloom in the Mary Snoddy garden in late-May to June, with flowers occurring at the top tips of the stems. The flowering period lasts several weeks. Plants reach heights up to three feet, in zones 5a through 9b. Flowers are red on the outside and yellow on the inside. The petal tips flare so that both colors are visible - gorgeous!

It takes several years for a newly planted Spigelia to reach its potential. Established clumps can be divided for propagation, but plants will reseed themselves if left alone. Flowers are followed by seed capsules that explode when ripe and spread their seeds around. It may take a year or two for those self-sown babies to bloom. Plants can also be propagated by cuttings taken in May, before flowering begins.

Appreciate Spigelia for its beauty but don’t be tempted to nibble. All parts are toxic, containing a form of strychnine poison.

Japanese Rose, Kerria japonica

The color yellow seems to own spring. Daffodils, forsythia, winter jasmine and Carolina jasmine are all in bloom. There is a spot of dark gold (“school bus yellow”) appearing in the woodlands. Kerria japonica (KARE-ee-ah jah-PON-ih-kah), known as Japanese Rose, has clusters of deep yellow blooms against bright green stems. Flowers appear before leaves. Kerrias are tolerant of heavy shade and inhospitable soils. They are unappetizing to deer. Flower color is paler in deep shade. Flowering is best in partial shade.

Japanese Rose has an arching habit similar to Forsythia. The shrub may reach heights of six feet or more, with an equal spread. It spreads by suckering and may grow into a hedge when left alone. To prevent spread, remove all suckers as soon as they appear. If desired, the plant can be pruned down to the ground to reduce its height. Any pruning should be done immediately after bloom season since most blooms occur on prior year’s wood. Any later pruning will reduce flowers for the following season. Stems branch in their second year of growth.

The narrow leaves turn yellow before they drop in autumn. Stems remain green throughout the winter. They have a zigzag growth habit similar to Cercis (Redbud). The cultivar ‘Pleniflora’ (sometimes listed on tags as ‘Plena’) has double flowers and is worth seeking. Its growth habit is a little more upright than ‘Golden Guinea’ which has an attractive single flower. ‘Picta’ has variegated foliage and stays smaller than the non-variegated types but is prone to reversion. If any non-variegated stems appear, prune them out immediately.

Kerrias are easily propagated from softwood stem cuttings or by removing and replanting suckers. If you have a steep bank in your woodlands (ditch or gully), use fast-growing Kerria to reduce erosion and turn an eyesore into a feature.

Yellow Kerria pompoms glow against arching green stems. This photo was taken in deep shade at Hatcher Garden and Woodland Preserve, Spartanburg SC.

Wary turtles watch as I photograph the nearby Kerria japonica.

Architectural Acanthus

One of my favorite plants for shade is Acanthus, (pronounced ah-KAN-thus) commonly called “Bear’s Breeches” for unknown reasons.  There are two species available in nurseries, Acanthus mollis and Acanthus spinosus. See the accompanying photograph for a side-by-side comparison.

Both species have bold evergreen leaves that draw attention in the garden. When you see one in bloom, you cannot help but say, “Golly!” The leaves of mollis are large and shiny; the leaves of spinosus bristle with sharp spines. (Bet you saw that one coming, huh?).  Leaf clumps may reach three feet tall. Bloom stems jump up to five feet or more. In the Mary Snoddy garden, the height of the bloom stem is a direct reflection of any irrigation I have thrown their way. The more water, the taller the stem. They do prefer a drier soil, however, so don’t get carried away with the watering. Ensure good drainage during winter to prevent root rot.

Acanthus’s distinctive leaves served as the pattern for carvings on classical Greek architecture. Blooms appear in early to mid summer on sturdy stems, white petals held by dusky purple bracts.

Acanthus are cold-hardy zone 7-10. They are evergreen in my zone 7b garden. Plants may spread by seed or by underground roots. I have seen reports of invasiveness on the internet, but have not experienced any such behavior in the ten-plus years I have enjoyed them. Deer, rabbits and voles avoid them.

Acanthus spinosus on left; Acanthus mollis on right.

Prickly Acanthus spinosus

Mary Snoddy and Acanthus mollis ‘Rue Ledan’