Plant of the Month for September, 2012

hypericum athoum header
Hypericum athoum

 (hy-PER-ee-kum ath-oo-um)

General Information:

There are over 400 Hypericum species and all have yellow flowers, usually with 5 petals. They can be annuals, perennials and even shrubs. Hypericum athoum is one of the jewels of the genus making a very nice clump that flowers much of the middle and late summer.

hypericum athoum main

Hypericum athoumphoto by Robert Pavlis

H. athoum makes a nice tight clump. Leaves are 8-15 mm long, ovate to oblong-ovate and softly hirsute (ie hairy). It forms clusters of 2 to 7 yellow flowers, about 15 mm in diameter. The flowers are quite large for the size of the plant.

hypericum athoum closeup

 Hypericum athoum; photo by Robert Pavlis

The common name, St. John’s wort is used to name many of the Hypericum species and is of little use in identifying plants.

A great rock garden plant that deserves to be grown more frequently.

Life Cycle: perennial

Height: 1o cm (4 inch)

Bloom Time: mid to late summer

Natural Range: Greece

Habitat: shady rocks, gravelly soil

Synonyms: none


Light: full sun to part shade

Soil: humus rich gravelly soil

Water: drought tolerant once established

USDA Hardiness Zone:  range not known – overwinters in zone 5

Propagation: seed and cuttings in late summer

Seedex availability (ORG&HPS annual Seed Exchange): available frequently

Sow @ 20°C. Seed germinates within 3 months.
Robert Pavlis