Overview
Acaena affinis is a matforming alpine rockery in the genus Acaena, part of the Rosaceae family, with evergreen foliage. It typically grows around 0.1-0.5 metres tall and 0.5-1 metres wide, reaching full size in around 2-5 years. Acaena affinis grows best in full sun and partial shade, and tolerates most soils and any pH. Its UK hardiness is rated H5. Suggested uses include gravel garden, patio and container plants, rock garden, ground cover and banks and slopes. It is native to South America and subantarctic islands.
About
Acaena affinis features sturdy, woody stems that lie flat and rarely take root, creating loose mats that reach up to 13 cm in height and can spread over 60 cm in width. The young stems exhibit a reddish-pink hue. Its pinnate leaves measure between 6 and 12 cm in length and consist of 9 to 13 prominently veined, blue-grey leaflets. The flowerheads are spherical and showcase red stamens. The burrs, which can grow 2 to 2.5 cm in diameter, are equipped with barbed spines and are supported by stems that can extend up to 20 cm long.
About the genus
Acaena comprises evergreen perennials or subshrubs characterized by pinnate foliage featuring serrated leaflets. The small flowers are borne in compact, rounded clusters or spikes, which subsequently give rise to distinctive burr-like fruiting structures.
Growing conditions
Best soil and position for Acaena
- Sunlight
- Full sun, Partial shade
- Soil type
- Chalk, Loam, Sand
- Soil pH
- Acid, Alkaline, Neutral
- Soil moisture
- Well-drained
- Aspect
- South-facing, West-facing, East-facing
- Exposure
- Exposed, Sheltered
- UK hardiness
- H5
Plant details
Acaena affinis size, habit and characteristics
- Plant type
- Alpine Rockery, Herbaceous Perennial
- Habit
- Matforming
- Foliage
- Evergreen
- Height
- 0.1-0.5 metres
- Spread
- 0.5-1 metres
- Time to full height
- 2-5 years
- Suggested uses
- Gravel garden, Patio and container plants, Rock garden, Ground cover, Banks and slopes
- Native to
- South America, subantarctic islands
- Toxicity
- Pets (dogs) - Burrs can irritate skin
Care notes
Pruning and caring for Acaena affinis
- Cultivation
- This plant is listed on Schedule 9 of the UK Wildlife & Countryside Act (Northern Ireland) as an invasive non-native species. Although not banned from sale, it is an offence to plant or cause these to grow in the wild IN NORTHERN IRELAND Gardeners possessing them should undertake measures to control them. See RHS advice on invasive non-native species for further information
- Propagation
- Please see cultivation notes
- Pest resistance
- Generally pest-free
- Disease resistance
- Generally disease-free
Frequently asked questions
How do I grow Acaena affinis?
This plant is listed on Schedule 9 of the UK Wildlife & Countryside Act (Northern Ireland) as an invasive non-native species. Although not banned from sale, it is an offence to plant or cause these to grow in the wild IN NORTHERN IRELAND Gardeners possessing them should undertake measures to control them. See RHS advice on invasive non-native species for further information.
Where is the best place to plant Acaena affinis?
Acaena affinis prefers full sun and partial shade. It suits exposed and sheltered positions.
What soil does Acaena affinis need?
Acaena affinis is adaptable and grows happily in most soil types, including chalk, loam and sand. It is happy in soil of any pH. Aim for soil that stays well-drained.
How big does Acaena affinis grow?
Acaena affinis reaches a height of 0.1-0.5 metres and a spread of 0.5-1 metres. It takes around 2-5 years to reach full size.
Is Acaena affinis hardy in the UK?
Acaena affinis has a UK hardiness rating of H5.
How do I propagate Acaena affinis?
Please see cultivation notes.
Is Acaena affinis toxic?
Pets (dogs) - Burrs can irritate skin.