Solomon’s seal is a distinctly attractive perennial for the shade with pretty white flower bells. This is how to plant and care for it.
Profile of Solomon’s seal:
Scientific name: Polygonatum multiflorum
Plant family: asparagus family (Asparagaceae)
Other names: David’s harp, ladder-to-heaven, Eurasian Solomon’s seal
Sowing time: autumn
Planting time: spring
Flowering period: May to June
Location: partially shady to shady
Soil quality: sandy to loamy, calcipholous, moderately nutritious, humus rich
These information are for temperate climate!
Use in: underplanting, borders, cottage garden, natural garden, forest garden
Winter hardiness: hardy, USDA Plant Hardiness Zones: 4 (-32 °C / -25 °F)
Bee and insect friendly: Yes
Plant characteristics and classification of Solomon’s seal
Plant order, origin and occurrence of Solomon’s seal
Solomon’s seal (Polygonatum multiflorum), also known as David’s harp or ladder-to-heaven, is a plant species of the asparagus family (Asparagaceae). Since the plant is often colloquially referred to simply as “Solomon’s seal”, there is a risk of confusion with the very rare angular Solomon’s seal or scented Solomon’s seal (Polygonatum odoratum), with which there is in fact a close resemblance. At first glance, it also resembles the false Solomon’s seal or treacleberry (Smilacina racemosa). Solomon’s seal is native to the temperate climate of Eurasia, where the perennial is found in loose loamy soils in the understory of deciduous and mixed forests. All parts of the plant contain saponins and are therefore poisonous.
Characteristics of Solomon’s seal
The Solomon’s seal is a deciduous, persistent perennial that spreads by rhizomes. These are nodular thickened, strikingly white. Polygonatum multiflorum grows between 60 and 80 centimeters (24 to 32 in) high and about 20 to 30 centimeters (8 to 12 in) wide, grows compactly upright and spreads slowly.
The lanceolate and on top dark green leaves of Solomon’s seal are alternate and arranged in two rows. They grow between 10 and 15 centimeters (4 and 6 in) long and about 5 centimeters (2 in) wide. They hang over in an arching manner. Some varieties also have bicolored, green and white striped foliage.
In May and June, bunchy, pendulous inflorescences appear with three to five small white to cream-colored flowers that are greenish at the tip. The nectar of the flowers is an ideal food source for bumblebees, bees and many other insects.
In August, the Solomon’s seal forms dark blue berries with a diameter of about 8 millimeters (0.32 in).
Solomon’s seal – cultivation and care
Solomon’s seal (Polygonatum multiflorum) requires a partially shady to shady location, preferably in front of or under woody plants.
The soil in the garden for the Solomon’s seal should be humus rich, loose, moderately moist to moist and well-drained.
The best time to plant out the plants is in early spring, because then Solomon’s seal in the same year decorate the garden with lush flowers. Freshly separated rhizomes are planted in the fall. Solomon’s seal should be planted in the bed according to their growth width. Make sure that the distance between them is at least 30 centimeters (12 in). In order for the plants to develop a dense bushy stand, you can plant ten plants per square meter (10 sq ft).
Keep the soil evenly moist during the growing season. Short dry periods do not cause problems for adult plants as long as the rhizome is not completely dry. Young plants should be watered more frequently during non-rainy periods so that the substrate is continuously moist. In the spring, you can mulch the soil. This promotes growth and at the same time ensures that the soil does not dry out.
If you mulch or mix compost under the substrate in the spring, no further fertilization is necessary during the year. Plants feed on nutrients throughout the growing season. Overfertilization can weaken the plant and cause disease or promote pest infestation.
Pruning measures are not recommended, as they weaken the Solomon’s seal. As deciduous plants, they extract their energy from the above-ground parts of the plant in the fall and store it in the rhizome. Once the leaves are completely withered, they can be cut off close to the ground. This measure is not absolutely necessary. The leaf mass protects the soil during the winter months and is decomposed. This gives the plants fresh nutrients the next spring, which they use for new shoots.
You can divide the fleshy roots of the plant in spring or autumn. To do this, carefully dig up the rhizomes and separate sections from the knotty root pieces. Replace them elsewhere in the garden.
The rhizome-forming plants can be propagated by division and thus be rejuvenated. To do this, dig up a healthy plant in the fall and divide a strong rootstock with a sharp knife. You can look for the nodular thickenings that serve as predetermined breaking points. Often rhizomes can be divided by breaking off a thickening. The section should have as many fine roots as possible so that it can grow more quickly in the new location. The mother plant should also have a sufficient network of fine roots.
The soil at the new location should be well loosened. A digging fork is perfect, as it penetrates to deeper layers of soil. Plant the cutting at the same depth where the mother plant is growing. Press the substrate and water the soil sufficiently so that holes close and the tuber grows better. In the next few years, do not disturb the daughter plant by digging. It takes some time to form new thickening at the root.
Solomon’s seal can also be propagated by seed. The seeds need cold to germinate and therefore need a cold stimulus. This can be done naturally by the onset of winter or artificially.
If you collect fruit in the fall, you should clean the seeds from the flesh and let them dry. Just before winter, sow the seeds directly in the open ground. Choose a partially shady location where the substrate has humus properties. When the snow melts the next year, the seed coat will swell and germination will begin. If you sow the seeds in the spring, germination also occurs after winter the following year.
You can positively influence the germination process by storing the seeds for four weeks in a warm place with temperatures of 20 °C / 68 °F. Sprinkle the seeds in a freezer bag filled with sand and store it in the refrigerator for four to six weeks. Regularly check the moisture of the substrate. This measure serves as stratification.
Then sprinkle the seeds on a potting compost and place the planter in a cool place with temperatures between 0 and 12 °C / 32 and 53 °F. Large temperature jumps should be avoided so as not to interrupt the germination process. As soon as the first leaves appear, the plants are pricked out. In April, the seedlings can be planted in the desired location in the garden.
Diseases and pests
There are no known diseases that cause problems for the Solomon’s seal. Droopy hanging leaves or reduced vigor are due to incorrect site conditions or care measures. Control moisture and lime content in the soil.
Many pests spread on plants that are already weakened. You can prevent infestations by spraying plants with garlic or horseradish broth in the spring.
Solomon’s seal sawfly
Solomon’s seal is the host plant of the Solomon’s seal sawfly, whose larvae can heavily feed on the plant’s leaves and flowers in the spring. This wasp species lays its eggs on Solomon’s seal leaves in May. An infestation is usually not noticed until the larvae have hatched and leave feeding marks in the leaves. They eat the leaves bare from the shoot tip to the leaf base, leaving a skeleton behind. Infested shoot tips should be generously cut off and removed to prevent the larvae from continuing to eat through the leaf mass. You can periodically scan the plant for pests and eggs and strip them from the leaves.
In the spring, slugs become annoying pests that feed on the freshly sprouting plants. They are particularly comfortable in the moist and shady locations where Solomon’s seal grows. Within a short time, these pests can eat entire stands bare. Loosen the soil regularly to make it harder for slugs to get in.
Help against slugs:
- Erect snail fences
- alternatively lay out pointed stones as obstacles
- Coffee grounds keep the pests away
- distribute snail nematodes with the watering water
Polygonatum multiflorum is winter-hardy and survives temperatures down to -32 °C / -25 °F. This high frost resistance is related to the natural location, because in forests the soil is protected by fallen leaves, so only in particularly severe winter months the top layer of soil freezes through. The root tubers lie at a frost-free depth.
In snowy winter months, a blanket of snow protects the soil of open gardens from freezing. If the snow cover is missing, you should cover the substrate with a thick layer of mulch. Fir branches, brushwood and leaves are suitable for this purpose. Alternatively, you can spread thick straw mats in the bed.
Use in the garden
Solomon’s seals are suitable for underplanting of woody stands. As typical forest species, the herbaceous plants decorate semi-natural gardens with old tree stands. They grow in border areas or perennial plantings and give rocky steppes a mystical character. Between lady’s mantle, foxglove and lily of the valley, Polygonatum multiflorum looks very elegant.
The foreground of wild hedges gets bright color accents with the graceful plants. They harmonize with rhododendrons, hostas and azaleas. Solomon’s seal cuts a good figure both in a group and in a single position. The herbaceous plant decorates early flower beds and makes a good planting for tubs and balcony boxes.