Westonbirt, the National Arboretum, is using a method to grow new plants from some of the collection's oldest and rarest rhododendrons.
The technique, known as air layering, tricks the plants into growing new roots from their branches. The roots produced are often stronger than those grown from cuttings because they have the live plant for support.
This is the first time the technique has been applied at the Forestry Commission managed National Arboretum in Gloucestershire. Good results will mean the team can grow new plants from rare hybrids introduced over a century ago by founder Robert Holford and his son, Sir George Holford.
The Holfords used selective breeding and seeds collected by famous Victorian plant hunters to create larger hybrid varieties to suit the extravagant gardening fashions of the era.
Amongst the plants the technique is being applied to is the Rhododendron griffithianum hybrid, 'Daphne Millais. The pink blooms differ from smaller varieties bred for the modern garden, marking the variety as a hallmark of Victorian and Edwardian taste.
Small areas of the rhododendron branch are wrapped with moss and rooting hormones then sealed in black plastic, locking out the sunlight and convincing the plant that it is underground. The roots are then left to grow on the plant until they are strong enough to be potted.
Penny Jones, propagator at the National Arboretum commented:
"The rhododendrons we want to reproduce are very exciting from an historical point of view; they represent one of the most significant periods of horticultural development at Westonbirt. Restoring and replanting these plants helps us to preserve the collection for visitors in the future.
"If the air layering method proves to be a success, the team at Westonbirt hopes to extend the propagation programme to include other rare varieties in the collection."
Rhododendrons start flowering in April and peak throughout May.
Entry to Westonbirt, the National Arboretum costs £8 adult, £7 concession, £3 child. Visit on a Wednesday in April and May and take advantage of half price admissions.
For more information contact 01666 880220 or go to www.forestry.gov.uk/westonbirt
Image attached: Daphne Millais rhododendron at Westonbirt Arboretum. Credit to Bev Starking.
Westonbirt - the National Arboretum is part of the Forestry Commission estate and is renowned worldwide for its tree and shrub collection. Home to the National Japanese Maple (Acer) collection, the National Arboretum covers 243 hectares (600 acres) and contains 16,000 specimens. Visitor numbers are 350,000 a year, with a membership of 23,000. Westonbirt Arboretum was established in the 1850s by wealthy landowner Robert Holford, and later developed by his son George Holford. Unlike many arboreta, Westonbirt is laid out according to aesthetic appeal rather than scientific or geographical criteria.
The Forestry Commission is the government department responsible in England for protecting, expanding and promoting the sustainable management of woods and forests and increasing their value to society and the environment. Further information can be found at www.forestry.gov.uk
Westonbirt - the National Arboretum is part of the Westonbirt Heritage Partnership, which consists of the Forestry Commission, Friends of Westonbirt Arboretum, Westonbirt School and the Holfords of Westonbirt Trust. The Partnership plans to reconnect the historic Westonbirt estate, conserve its unique heritage and inspire future visitors through the Westonbirt Project.
The Friends of Westonbirt Arboretum was formed in 1985. The charity's objects are to support the National Arboretum in promoting public understanding of the crucial role of trees to the environment and society. It is funded by membership receipts from 23,000 members, other fundraising, and the use of the Great Oak Hall for events and activities.
Source: Westonbirt - The National Arboretum