Common Name: Hardhack

General Information

Spiraea tomentosa is a deciduous shrub with erect to ascending stems that are seldom branched; it can grow 30 - 150cm[]. The plant spreads by means of subterranean suckers to form thickets[11 200].
The plant is harvested from the wild for local use as a medicine. It is grown as an ornamental in gardens.
The plant has escaped from cultivation and become invasive in parts of Europe.

Known Hazards

None known

Botanical References

,

Range

N. America - Manitoba, Ontario and New Brunswick, south through eastern N. America to Mississippi and South Carolina

Habitat

Fields and pastures in N. America[]. Swamps and low ground[]. Wetlands, woodland borders with moist acidic soil; at elevations up to 1,500 metres[].

Properties

Medicinal Rating
Habit	Deciduous Shrub
Height	1.50 m
Pollinators	Insects
Cultivation Status	Wild

Cultivation Details

Tolerates most soils[], but prefers a good loamy soil, abundant moisture and full sunlight[, ].
A vigorous plant, spreading by subterranean suckers and forming thickets[].
Closely related to Spiraea douglasii, and often confused with it[].
Species in this genus generally hybridize freely with other members of this genus, and so seed cannot be relied upon to come true unless the plant has been grown in isolation from other species that are flowering at the same time[].
The plant is apt to become thin and poor unless it is divided up fairly regularly and replanted in fairly good soil[, ].
The shoots that flowered the previous summer should be pruned back in late winter or early spring in order to promote better flowering[].

Edible Uses

None known

Medicinal

The flowers give feebly the medicinal action of salicylic acid (aspirin) and are used in decoction for their diuretic and tonic effect[]. An infusion of the flowers is used as an astringent[].

An infusion of the leaves can be used in the treatment of dysentery[].

An infusion of the flowers and the leaves has been used to counteract the sickness of pregnancy and also to facilitate childbirth[].

The roots are astringent and have been used in the treatment of diarrhoea[, ]. An infusion of the leaves is also used[, ].

Other Uses

None known

Propagation

Seed - we have no information for this species but suggest sowing the seed as soon as it is ripe in a cold frame if possible. It is likely to require stratification before it germinates, so stored seed should be sown in a cold frame as early in the year as you receive it. Prick out the seedlings into individual pots when they are large enough to handle, and grow them on in a cold frame for their first winter. Plant them out in late spring or early summer of the following year.
Cuttings of half-ripe wood, mid summer in a light sandy soil a frame.
Cuttings of mature wood of the current seasons growth, 15cm long, autumn in an outdoor frame[].
Division of suckers in early spring[]. They can be planted out straight into their permanent positions.