Solomon's seal (Polygonatum) is a genus of elegant woodland plants that are native to North America. Although the small, tubular flowers—which come in white, green, or pink—are charming, it's the slender arching stems and lance-shaped leaves that make Solomon's seal such a favorite in shade gardens and woodland settings. Once established, Solomon’s seal slowly spreads and creates a blanket of foliage that turns a golden yellow in autumn.
Size varies among the species. Most of Solomon's seal plants grow to around 1 to 2 feet tall. There is a giant Solomon's seal (Polygonatum biflorum var. commutatum) that reaches around 5 feet tall or higher and really makes a statement in the garden. These plants grow at a moderate pace and can take a few years to bloom when grown from seed. They can be planted in the spring or fall.
|Common Name||Solomon's seal|
|Plant Type||Herbaceous perennial|
|Mature Size||6 inches to 7 feet tall (depending on species)|
|Sun Exposure||Part shade to full shade|
|Soil Type||Rich, humusy, moist, well-draining|
|Soil pH||5 to 7|
|Flower Color||White, green, pink|
|Hardiness Zones||3 to 9|
|Native Area||North America|
How to Grow Solomon's Seal
Solomon's seal plants are native to woodland areas, so they prefer to grow in a spot with some shade and dampness. Gardeners usually start their plants with transplants or rhizomes (underground stems that produce new plant shoots). Seeds of Solomon’s seal can take up to two years to sprout.
Solomon’s seal does not require deadheading (removing spent blooms). The flowers are small and will drop off naturally. Plus, the foliage remains attractive for the entire growing season (spring to fall), so the plant is virtually maintenance-free with no need for pruning. The stems even disconnect from the rhizomes on their own after frost in the fall.
Solomon's seal plants are naturally found growing under large shade trees in dappled light. So an ideal planting site in your garden should have partial to full shade. They can tolerate more sun when grown in cooler climates than they can in warmer climates.
These plants like cool soil that’s rich in organic matter and has good drainage. A slightly acidic soil pH is ideal. To increase the richness of your soil, it can be helpful to add a layer of compost around your Solomon’s seal each year.
Solomon's seal plants prefer soil that remains evenly moist but not soggy. Young plants should be watered regularly to maintain consistent moisture in the soil. Established plants still prefer to be in soil that is damp to the touch, though they can tolerate short periods of drought if necessary.
Temperature and Humidity
The various species of Solomon’s seal can grow in USDA hardiness zones 3 to 9. While they prefer cool and shady environments with some humidity, they can successfully grow in hot and dry climates with some help. Make sure the plants have ample soil moisture and shade, as well as protection from strong, hot winds. Plus, a layer of mulch around the plants can help to keep their roots cool. In the fall, frost will cause the plants to begin to die back to their roots for the winter.
Because this plant likes to grow in plenty of organic matter, mix some compost into the soil of your garden site when first planting Solomon's seal to give it a good start. Then, continue to add an organic fertilizer or compost each year at the start of the growing season to give your plant a boost, especially if you don't have naturally fertile soil.
Common Pests and Diseases
Healthy Solomon's seal plants growing in optimal conditions have few problems with pests and diseases. If the weather is extremely damp, you might see signs of a fungal disease, which can appear as discoloration on the foliage. Ensuring good air circulation around the plant can help to prevent and combat such issues. Slugs and snails can also become a problem, so watch out for holes in the leaves and stems. There are several natural methods that can combat these pest problems.
Varieties of Solomon's Seal
There are more than 60 species within the Polygonatum genus. The species have very similar growing requirements but can range in size, coloring, and other factors. Some popular varieties include:
- Polygonatum biflorum: This species grows roughly 1 to 3 feet tall. Its leaves are smooth on both sides, and the plant features white-green flowers.
- Polygonatum odoratum var. pluriflorum 'Variegatum': This plant reaches around 2 to 3 feet tall, and its leaves have white edges. The white flowers have a sweet fragrance reminiscent of lilies.
- Polygonatum 'Prince Charming': This variety only grows to about a foot tall, but it spreads to around 2 to 3 feet wide. 'Prince Charming' plants tend to bloom at a younger age than many other Solomon's seal plants and feature greenish-white flowers.