The National Plant Collection of Artemisia- Dr John Twibell
Artemisia is a diverse genus of plants within Compositae (Asteraceae), composed of about 400 different species. The composite flowers are largely insignificant as they do not have the outer ray sepals typical of other daisy-type flowers. Most cultivated artemisias are used for their architectural appearance, strong scent or for herbal uses rather than for their flowers, although some of the flowering stems make attractive dried flower arrangements. The silver leaved species are particularly prized both as garden plants and for drying. Some of the scented plants are useful in pot pourri or have long associations as natural insect repellents.
Most species are successful colonisers of waste or marginal land in their native habitat, although some are endangered. Many of the larger herbaceous species are from similar climates to our own (UK) and will tolerate most garden conditions. Others originate from warmer climes and are best accommodated in well-drained soil in sheltered sunny positions. The low growing shrubby silver species mainly originate from mountain or desert areas and are best suited to sink gardens or to very well drained soils. Whilst most of the more erect ever-silver plants largely survive without protection if the drainage is good, a few of the prostrate true alpines require protection from excessive winter wetness.
British Natives
There are six native species; the commonest and most widespread it mugwort Artemisia vulgaris which is a frequent roadside weed and was formerly widely cultivated to preserve ale. Wormwood (A.absinthium )is less common but grows in sandy places ,often along river banks. Sea wormwood (A. maritima) is a short silver plant confined to coastal salt marshes and occasionally found on jetties and banks subject to sea wash or spray. The field wormwood (A. campestris subsp. campestris) is nowadays only found in the Breckland area of Norfolk and Suffolk, but the maritime form (A. campestris subsp. maritima /A. crithmifolia) is now known at only two sand dune sites at Crymlyn Burrows in S Wales and on the Crosby dunes near Merseyside. The Norwegian wormwood (A. norvegica) is confined to a few mountain top sites in Wester Ross.
Artemisia Collection
Dr John Twibell became interested in the diversity of these plants and started to collect them in the early 1980s. The collection was designated as a National Plant Collection in 1988 and was given Scientific status in 1997.
The collection was originally held near Cambridge but moved to Sidmouth, Devon in 2007. It is continually expanding and currently holds over 300 accessions. Although more are added each year, inevitably a few are lost each winter due to difficulties in maintaining the correct environment for so many varied species.
Plants are sold from the collection to promote artemisias and to ensure that wherever possible correctly assigned material is available, and to produce finance for the collection.
© Dr John Twibell
Read about Artemisias in British Cultivation