Underutilized Landscape Plants: Let's Talk Native Perennials

Here are three native perennials to consider adding to your portfolio of landscape plantings.

Porteranthus trifoliathus (Gillenia trifoliata)

Bowmans's root, Indian Physic

Bowmans's root, or Porteranthus trifoliathus, is a study in contrasts. It boasts delicate white, star-shaped flowers in May-June but has a robust shape and appearance. This highly ornamental perennial blooms in May and June in PA and throughout USDA zones 4-8. Porteranthus trifoliathus is native from Ontario east, south to Georgia, and west to Arkansas. It prefers moist, humusy, well-drained soil in full to part sun. The warmer the area, the more shade it prefers. Bowmans's root is a mounded 2-3 ft tall and 3 ft wide deciduous perennial. Once established, it is very drought tolerant.

In addition to the ethereal blooms, Bowmans's root boasts red calyces that persist after the flower petals drop and beautiful red fall color. It is pollinator and butterfly-friendly but resistant to herbivory from mammals, i.e., deer. This native has few pests and needs little maintenance. Bowmans's root looks excellent at the edge of a woodland, in a meadow, in a mass, or as a specimen. I like to use it with the tall spires of foxgloves, the substantial flowers of Baptisia, or mixed with Astrantia and roses. At the feet of the roses, Bowmans's root, and Astrantia, you could add a punch of color with Callirhoe involucrata, poppy mallow. Porteranthus blooms are available in white (straight species) and pink (Pink Profusion). I love the white, but you can see that pink also has its charms in the picture.

Figure 2. Porteranthus Pink Profusion flowers (left) and plant (right). Photos: Margaret Hoffman, Penn State

Figure 3. Porteranthus white. Photos: Margaret Hoffman, Penn State

Spigelia marilandica

Indian Pink

Spigelia marilandica is now more available in the nursery trade. Because it is a long-blooming native perennial, it will grow in the shade and is a top ten hummingbird plant. There is no reason not to grow this attractive addition to our gardening palette. Add to this the spectacular tubular red and yellow flowers and their ease of cultivation, and really, what's not to like?

While Indian pink is not native to Pennsylvania, it is a southeastern US native perennial, hardy in zones 5-9. Its size allows it to fit into most gardens, growing to 1-2 ft tall and ½ -1 ft wide. It grows in clumps and has a spectacular bloom period in June, followed by sporadic blooming throughout the summer. Average, well-drained soil in full to partial shade is all that is needed for a happy plant. Some sources suggest it will tolerate wet soil, but not for prolonged periods. It is pest and disease free, deer and rabbit resistant, and does not require division.

Figure 4. Spigelia marilandica, Indian Pink. Photo: Margaret Hoffman, Penn State

Landscape uses include planting in bioswales, woodland gardens, or along paths. The upraised, red tubular flowers with yellow firecracker stars encourage clients to stop and admire. Try interplanting with eastern red columbine (Aquilegia canadensis) to echo the yellow and red contrasts.

Aruncus dioicus

Goatsbeard

Goatsbeard is a large PA native perennial that will make quite a statement in your garden. The plumelike flowers and the finely dissected foliage resemble very large astilbe. The blooms are cream in color and last for about ten days. According to the Missouri Botanic Gardens, Goatsbeard occurs naturally in moist and wet areas in the temperate northern hemisphere, basically zones 4-8. Our Pennsylvania native variety is Aruncus dioicus var. dioicus. There is a variety native to western and central Europe, Aruncus dioicus var. vulgaris, and a lovely delicate Korean dwarf variety, only 8-12 inches tall, Aruncus aesthusifolius. Although hardy to zone 8, goatsbeard struggles south of zone 7. In Pennsylvania, it blooms in May, although while visiting the Minnesota Landscape Arboretum on June 21, it was still blooming. The goatsbeard in these pictures is in full sun, but they receive irrigation. They had just experienced a week of over 90-degree weather and still looked lovely.

Goatsbeard does well in medium to wet soils high in organic matter and enjoys full sun to part shade. The more sun, the more moisture is needed. It wants a mulch of shredded leaf litter to keep the soil cool and moist, but overall maintenance is low. There are seldom insect or disease problems, although leaf appearance suffers when placed in full sun without sufficient moisture. Site this plant correctly because once established, the plant attains a large size, 4-6 ft tall and 2-4 ft wide, and does not transplant well. It does spread rhizomatously but in a well-mannered fashion. This native perennial is another plant that tolerates deer and rabbit herbivory. When designing with goatsbeard, remember it is slow to establish and takes a few years to attain its shrublike proportions.

Figure 5. Aruncus dioicus flower (left) and Aruncus in shade. Photos: Margaret Hoffman, Penn State

Designers can use goatsbeard in pollinator gardens; it attracts bees and butterflies, and as an added plus, it is a host plant for the Dusky Azure butterfly. Goatsbeard is often used to good effect edging a walkway. If used as an edging plant, be sure to site 3-4 ft from the path's edge so clients are not forced off the walkway. Goatsbeard combines well in a perennial border with purple Siberian iris (Iris sibirica), Hosta 'Sagae' (Hosta sp. 'Sagae'), Star of Persia (Allium christophii), giant onion (Allium giganteum), native Solomon's seal (Polygonatum commutatum), or monkshood (Aconitum napellus or A. carmichaelii 'Arendsii'). As long as the soil does not experience sustained dryness, it is an excellent addition to rain gardens. Goatsbeard is a great choice for woodland transition areas and looks terrific next to ponds and streams.

Sources

Missouri Botanic Garden