Solomon’s-seal (Polygonatum biflorum and other species) produce small, greenish-white, dangling flowers at the stem joints. Typically, one to three flowers are clustered together. Bumblebees are frequently seen pollinating their flowers.
Joey Williamson, ©2020 HGIC, Clemson Extension
Native Solomon’s-seals (Polygonatum biflorum), as well as other Polygonatum species, generally emerge in late March to early April and immediately begin flowering. They have an unusual plant texture with their arching stems and dangling white flowers. Solomon’s-seals are easy to grow, and with their spreading rhizomes, they will form small colonies by year’s end.
Solomon’s-seals prefer shaded to partially shaded landscape sites with well-drained, acidic soils that are high in organic matter. Therefore, when planting, be sure to amend the soil with compost or a soil conditioner. To improve the nutritionally quality of the soil and to give a boost to root growth, amend the planting holes for these and other perennials with an organic fertilizer, especially one that is labeled to contain beneficial soil bacteria.
Native Species
Large Solomon’s-seal (Polygonatum biflorum var. commutatum) is the taller, but less common of the natives and may reach 6 feet tall. Here the pairs of flower buds have formed and will soon open to produce hanging white flowers.
Joey Williamson, ©2020 HGIC, Clemson Extension
There are three Solomon’s-seals that are native to South Carolina, but the most common are the Small Solomon’s-seal (P. biflorum var. biflorum), which grows to 1 to 3 feet tall and the Large Solomon’s-seal (P. biflorum var. commutatum), which may reach 3 to 6 feet tall. Both are very similar in flower, and both produce small, round blue fruits during the late summer. These fruits are a favorite of songbirds. A lesser common Solomon’s-seal is the Downy Solomon’s-seal (P. pubescens), which grows in the upper Piedmont of northwest South Carolina.
Solomon’s-seals belong to the plant family Ruscaceae, which also includes lily-of-the-valley, mondo grass, and liriope.
The rhizome (an underground, spreading stem) is jointed where the above-ground stem attaches. After the first autumn frost, the above-ground stems senesce and detach from the rhizomes. The round speckled scar from the point of stem attachment is where these plants get their name.
Joey Williamson, ©2020 HGIC, Clemson Extension
The common name of these woodland beauties comes from the leaf stem scar, where it attaches to the rhizome or underground stem. In autumn, after a frost, the upper portions of the plant senesces (that is, the plant turns yellow and dies back) and breaks off from the rhizome. Where it was attached, there remains a round scar that resembles the Seal of King Solomon.
Propagation
Propagation by seed requires a cold, moist treatment for two months. Collect the ripe, blue fruit, remove the seeds, and discard the pulp. Mix the seeds with a small amount of moist sphagnum moss and place them in a sealable sandwich bag. Refrigerate the bag in the vegetable crisper section of the refrigerator for two months. Finally, remove the seed and plant them in a seed propagation medium (a fine-textured potting soil). Place containers in a shady area and keep the soil medium moist.
Similar Species
A very similar woodland perennial that may be confused with the Solomon’s-seal is the Eastern Solomon’s–plume (Maianthemum racemosum). It, too, is a native woodland perennial with arching stems, but the white cluster of flowers are produced on the ends of the stems. It produces fruit by late summer that are a marbled, rosy-red.
Although not a native, Variegated Solomon’s-seal (Polygonatum odoratum var. pluriflorum ‘Variegatum’) is an extremely drought tolerant perennial for shady woodland gardens. The plants die back in winter with the first frost, but the foliage always looks superb throughout the spring and summer months.
Eastern Solomon’s–plume (Maianthemum racemosum) is a closely related woodland perennial, but the flowers are produced in clusters at the ends of their arching stems. It is also native to South Carolina.
Joey Williamson, ©2020 HGIC, Clemson Extension
Variegated Solomon’s-seal (Polygonatum odoratum var. pluriflorum ‘Variegatum’) is an extremely drought tolerant perennial for shady woodland gardens.
Joey Williamson, ©2020 HGIC, Clemson Extension
Problems
Foliar nematodes can severely damage the leaves of Solomon’s-seal. Brown stripes indicate damage by the nematodes as they feed between the parallel leaf veins.
Joey Williamson, ©2020 HGIC, Clemson Extension
Rarely do Solomon’s-seals have any disease or pest problems, but they are susceptible to foliar nematodes. Foliar nematodes can also ruin hosta and fern foliage. As they feed within the leaf tissue, their movement is limited by the leaf venation, so the damaged areas appear as brown stripes on the leaves. There are no consumer pesticide treatments; therefore, prompt removal and disposal of infested foliage is the best means of control. Do not use over-head irrigation on Solomon’s-seal, as the splashing of water may allow for the movement of the nematodes to additional leaves.
Phyllostica cruenta is a fungal pathogen that causes tan leaf spots with dark reddish-brown margins.
Joey Williamson, ©2020 HGIC, Clemson Extension
Phyllosticta cruenta is a fungal foliar pathogen that makes small tan spots with reddish-brown halos on Solomon’s-seal leaves. The center of the leaf spots may tear, creating holes in the leaves. Prompt removal of the initially infected foliage may eliminate or slow the progression of the disease. Do not water with overhead irrigation, as wet foliage may increase the incidence of disease. If fungicide sprays are required, daconil (chlorothalonil) should give good control.
Companion Plants
Many perennials make good companions to Solomon’s-seals in partially shaded woodland beds, such as Christmas ferns, Japanese painted ferns, heucheras, hostas, foam flowers, woodland phlox, lungworts, and bellworts.
Solomon’s-seals are easy to grow, reliable perennials that will give years of enjoyment and make a wonderful addition to any woodland garden.
References:
- Flora of the Southeastern United States. Alan S. Weakley, October 2020.
Originally published 01/21
