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.
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 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 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.
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.
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.
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.
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.
- Flora of the Southeastern United States. Alan S. Weakley, October 2020.