Originally grown in Tudor times for medicinal use, astrantias gained wider popularity as their unusual blooms, with star-shaped bracts surrounding an endearing dome of tiny flowers, were worked on by breeders who increased their size and the colour range.
These are accommodating plants, naturally well suited to coping with the changes we’re currently seeing in our climate. Adaptable enough to cope with wet in winter and drier soils in summer, astrantias are very cold hardy and can be grown in shade or sun.
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They’re also long-flowering, especially some of the modern, sterile cultivars, and their umbelliferous flowers are popular with pollinators. They even make excellent, long-lasting cut flowers.
Astrantia fact file:
- What A genus of ten accepted species of hardy, clump- forming perennials with lobed, green leaves, in the umbellifer family (Apiaceae). Upright stems carry compact umbels of small, pincushion-like flowers surrounded by stiff, petal-like bracts in shades of white, pink and red. Often called masterwort, which relates to their early medicinal use, and sometimes Hattie’s pincushions.
- Season Mainly late spring to midsummer, but they can carry on into late summer and autumn.
- Size 30-70cm tall.
- Conditions Rich, moisture- retentive soil in light shade or sun.
- Origins Found in alpine woods and meadows in mountainous areas of Europe extending east to the Caucasus.
- Hardiness Hardy throughout the UK with an RHS hardiness rating of H7, and suitable for gardens in USDA zones 4a to 7b.
There are ten accepted species of Astrantia, originating in the heavy, damp soil of alpine meadows and the margins of woodland in mountainous areas. Of these, there are three species that are commonly grown in the UK, plus a few more occasionally found for sale, such as Astrantia bavarica.
Their informal style and muted hues have seen astrantias become a cottage-garden favourite, but they’re also ideal candidates for shady town gardens, perhaps planted with hydrangeas, shade-tolerant geraniums and tree ferns.
Their informal style and muted hues have seen astrantias become a cottage-garden favourite
Their adaptability and colour range makes them easy to place in herbaceous borders and they have the sophistication to work well in contemporary schemes, among short grasses such as blue-leaved oat grass Helictotrichon sempervirens, pewter-leaved heucheras or ferns such as the painted lady fern, Athyrium niponicum var. pictum.
How to grow Astrantia
Astrantias like rich soil with plenty of organic matter, ideally moist soil in light, dappled shade, but they are adaptable, and can be planted in sunny borders where the soil doesn’t dry out too much. They can cope with periods when the soil is wet, so don’t rule out areas that might be waterlogged for short periods in winter. Astrantias don’t do well in containers, but some smaller cultivars might work.
Astrantias are naturally well suited to coping with the changes we’re currently seeing in our climate
Where to plant astrantia
Dig a hole larger than the rootball and plant so that the crown of the plant, where the leaves and stems emerge, is at the surface of the soil. After planting, make sure to water regularly if there isn’t much rain, especially if planting in spring and the weather is warm. Plants should be able to cope with dry periods once they are growing strongly, but water any that start to flag as soon as possible.
When to plant astrantia
The best times to plant astrantias are early autumn or early spring, so plants have time to establish either before going into winter dormancy or before the warmer, drier weather of late spring and summer are underway.
How to propagate astrantia
Large clumps can be divided in spring by digging up the whole plant, dividing it into sections and replanting them or potting them up straight away. Divisions may take a while to recover and flower again, as astrantias don’t like to be disturbed.
Plants can also be grown from collected seed. Wait until the heads are dry and brown and the seed is ripe, then sow straight away, leaving the seed tray in a cold frame over winter. Some may germinate in autumn, but they benefit from cold stratification so are more likely to germinate in spring. Seedlings that crop up around existing plants could also be potted up. Seedlings from cultivars are unlikely to be the same as the parent plant.
When do astrantia flower
Astrantias are an excellent source of pollen and nectar. Their small flowers attract short-tongued pollinators such as hoverflies, beetles and smaller bumblebees, while their long flowering period means they provide sustenance from early summer to autumn.
This long flowering season also allows plenty of time to enjoy the delicacy of the exquisite flowers, and when they do fade, you can deadhead them or cut the whole plant back hard, and new foliage should soon regrow, leading to a smaller second flush of flowers to last into early autumn. Deadheading also reduces the proliferation of seedlings that all but the sterile cultivars tend to throw up.
As flowers fade, they can be individually deadheaded or, if the whole plant is going over, it can be cut back hard, including taking off the old foliage, and allowed to re-grow and re-flower later in the season. The second flush is normally smaller than the first. Limiting the number of seedlings left to grow is good practice to avoid overcrowding.
How to treat disease in astrantias
Astrantias have few pest or disease problems. They may be affected by powdery mildew if the soil is too dry, and they may suffer from astrantia leaf miner, which can be seen as silvery tunnels in the leaves, but this rarely has any serious effect on their health or flowering. Many people swear they remain untouched by slugs, while others find them ravaged on a regular basis.
The best Astrantia to grow
Astrantia major ‘Pink Sensation’
Astrantia major 'April Love’
Astrantia major ‘Pink Pride’
Astrantia ‘Buckland’
Astrantia ‘Ruby Star’
Astrantia major Gill Richardson Group
Astrantia ‘Burgundy Manor’
Astrantia major subsp. involucrata ‘Moira Reid’
Astrantia major ‘Can Candy’
Astrantia major ‘Venice’
Astrantia major ‘Large White’
Where to see and buy astrantia
- Letham Plants 11A Letham Mains Holdings, Haddington, East Lothian EH41 4NQ. letham-plants.co.uk
- Norwell Nursery Woodhouse Road, Norwell, Newark, Nottinghamshire NG23 6JX. National Collection holder. Tel 01636 636337, norwellnurseries.co.uk