Sweet briar

Scientific name: Rosa rubiginosa

Sweet briar flowers

Sweet briar flower

Sweet briar rosehips

Sweet briar
  • Key characteristics
  • Biology
  • Impacts
  • Control
  • Further information

  • Large perennial much-branched, scrambling or upright rose, up to 3m, with single pink flowers followed by bright red rose hips
  • Stems are woody but smooth and green/reddish between the multiple prickles
  • Prickles are of unequal sizes, usually hooked downwards but sometimes pointing straight out
  • Fragrant, simple, pink flowers, each 2-5 cm wide, bloom in loose clusters of 1-3 at the tips of the branches in late spring and summer. Each flower has 5 pink to white petals, 8-25 mm long, and many stamens
  • Leaves alternate on the stem, each leaf made up of 2-4 pairs of oval leaflets with one terminal leaflet. Leaf stem has prickles on its underside. Leaflets are about 1-3.5 cm long and 1-2.5 cm wide with toothed margins, and produce an apple-like fragrance when crushed
  • Fruits (hips) are oval to egg-shaped, and initially green in colour before maturing to yellow, orange or red berries 1.5-2 cm long. The fruit usually has a few straight spines, often accumulated towards the very spiny stem of the fruit. Remains of sepals often persist at the top of the fruit
  • Seeds are 4-7 mm long, yellow, and irregularly shaped
  • Flower stalk and lower leaf surface have glandular sticky hairs.

Origin

  • Native to Europe, western Asia and north Africa
  • Originally introduced to New Zealand as an ornamental rose by early European settlers. The species was widely used as the rootstock for grafted roses. However, the practice no longer continues
  • Charles Darwin recorded the presence of sweet briar in gardens at Paihia in 1835
  • The plant spread beyond gardens and was classified as a noxious weed throughout the country in 1900
  • In the early 1950s, the weed spread rapidly into South Island high country following rabbit control and subsequent reduced grazing pressure.

Life cycle and habitat

  • Sweet briar matures slowly and only flowers at about 3 years of age
  • Spread by cattle, possums and birds eating the fruit and as a result dispersing the seeds
  • Seedlings readily establish where rabbits have reduced pasture vigour
  • New plants are very susceptible to competition and do not easily establish in competitive pastures. However, established plants are very competitive
  • Can be found in tussock grassland, waste areas, flats, terraces and banks, riverbeds and roadsides in cooler temperate/sub-tropical regions and usually develops on the more fertile sites. Seedlings can sometimes be found in cow pats.

Benefits

  • Sweet briar used to be cultivated as a garden ornamental and was also used as  a hedging plant
  • Potential benefits of sweet briar are as a source of rose-hip syrup or a source of fodder for goats
  • Hips of sweet briar can be collected as a valuable source of vitamin C.

Occurrence

  • Sweet briar is a major scrub weed in parts of the South Island and a road-side weed of the North Island, especially in the Central Plateau
  • Grows extensively in Marlborough, South Canterbury and inland Otago. It is also found on Stewart and Chatham Islands
  • Sweet briar grows in tussock grassland and poor pastures (particularly with stony ground and little rain) where competition is limited
  • The plant is associated with extensively grazed grassland and light scrubland.

Impact on pasture

  • Sweet briar is very competitive once established, can prevent other plants from growing near it, and livestock are deterred from grazing close to it
  • Usually grows in good potential forage areas and can obstruct the free passage of livestock.

Grazing management

  • Goats can effectively control sweet briar but must be fenced in close to it to prevent selective browsing.

Other methods

  • Can be discouraged by planting competitive pasture species which will help prevent its establishment
  • Hand grubbing, bulldozing and root raking can be used to remove established plants.

Chemical control

  • When economically viable, metsulfuron, glyphosate or triclopyr + picloram can control sweet briar, but re-establishment may be an issue
  • Spot treatment with spray or prills, or cut stump treatment with picloram gels are all good methods for controlling plants in pasture.

ALWAYS READ PRODUCT LABELS BEFORE APPLYING

Active ingredient When to apply Residual effect Grass Damage Clover Damage
glyphosate spring/summer none severe Severe but temporary
hexazinone anytime long severe severe
metsulfuron spring/summer short moderate moderate
picloram (gel) apply to freshly cut stump anytime short very slight severe
picloram (prills) late winter/early spring moderate very slight severe
picloram/metsulfuron spring/summer moderate moderate severe
picloram/triclopyr spring/summer moderate very slight severe
triclopyr spring/summer short very slight severe

  • Popay I, Champion P, James T 2010. An illustrated guide to common weeds of New Zealand. New Zealand Plant Protection Society, Christchurch, New Zealand. 416 p.
  • Young S 2013. New Zealand Novachem agrichemical manual. Agrimedia Ltd., Christchurch, New Zealand. 767 p.
  • Weedbusters NZ, 2016, Rosa rubiginosa factsheet (accessed 17 October 2016)