Astrantia carniolica ‘Rubra’ Astrantias are superb perennials for growing under trees, on a stream bank or in a moist border. They prefer moist soils but will tolerate drier conditions as long as the plants are mulched. Astrantia carniolica ‘Rubra’ is a dwarf variety, growing no taller than 45cm. It bears rich maroon-coloured flowers and bright green bracts.
An ideal soil would be made up of 45% minerals (sand, clay, silt), 5 % organic (plant and animal) material, 25% air and 25% water. The mineral portion would be loam (20 – 30% clay, 30 – 50% silt and 30 – 50% sand).
After flowering, astrantias can be rejuvenated by cutting them back close to the ground – fresh new foliage and a late crop of flowers are produced soon after. Astrantias don't spread far but they do self seed. Like geranium (cranesbill), the whole plant can be cut down to ground level following the first flush of flowers in July, to stimulate fresh growth and further flowers.