King Solomon's Seal, Smooth Solomon's seal
Polygonatum commutatum

Family: Convallariaceae

What it is like

Polygonatum commutatum is a PERENNIAL growing to 2 m (6ft) by 0.6 m (2ft in). See above for USDA hardiness. It is hardy to UK zone 5. It is in flower in May. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees. The plant is self-fertile. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in full shade (deep woodland) or semi-shade (light woodland). It prefers moist soil.

Height (m): 2

Where it is found

Moist woodland and copses, often by streams. Plants are rarely found in dry soils.

Eastern N. America - Rhode Island to Ontario and Manitoba, south to Georgia, New Mexico and Arizona.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 2

Young shoots - cooked. They can be used as an asparagus substitute. Root - cooked. A parsnip-like flavour. Rich in starch, it can be dried and ground into a powder then used as a thickener in soups etc or can be added to flour when making cakes, bread or whatever. The root should be boiled and sun-dried nine times, it is then delicious (if there is anything left!)

Root: includes bulbs, corms, tubers, rhizomes etc.

Medicine

Rating: 1

A decoction of the root has been used as a herbal steam inhalant as a treatment for headaches.

Analgesic: Relieves pain.

Other

Rating:

The root has been burnt in the house for its pleasant fragrance.

Incense: Aromatic plants that can be burnt to impart a pleasant smell, repel insects and disinfect closed areas.

Food Forest: Plants for Edible Forest Gardens and Food Forests.

How it is grown

Prefers a fertile humus rich moisture retentive well-drained soil in cool shade or semi-shade. Plants are intolerant of heat and drought but tolerate most other conditions. Grows well in woodlands and copses. Members of this genus are rarely if ever troubled by browsing deer or rabbits. The young shoots are very attractive to slugs. Hybridizes with other members of this genus. According to one report this species is no more than a synonym for P. biflorum.

Propagating it: Seed - best sown as soon as it is ripe in early autumn in a shady part of a cold greenhouse. Sow stored seed as early in the year as possible. Germination can be slow, they may not come true to type and it takes a few years for them to reach a good size. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in a shady position in the greenhouse for at least their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. Division in March or October. Larger divisions can be planted out direct into their permanent positions. We have found that it is better to pot up the smaller divisions and grow them on in light shade in a cold frame until they are well established before planting them out in late spring or early summer.

Best place to grow: Woodland Garden Dappled Shade; Shady Edge; not Deep Shade;

Habit: Perennial

Hardiness: 4-8

Growth:

Soil: Light (sandy), medium, heavy (clay)

Shade: Full shade, semi-shade

Moisture: Moist

Things to keep in mind

The fruit and seed are thought to be poisonous.

Its other names

Local names

Synonyms

P. canaliculatum. P. giganteum.