Hardy Hybrids

Longstock Gem

B. ‘Longstock Gem’  is a very early flowering Buddleja, flowering before B. alternifolia. The flowers are larger than B. alternifolia with a scent. Attractive oak shaped leaves which are alternate on some shoots and opposite on other shoots changing to maroon and yellow in the autumn.

It will make a large plant good for screening, remove all the old flowering branches. If it does become too large hard prune to the ground in June

This is a sterile Buddleja. DOES NOT SET SEED.




A hybrid between B. agathosoma x B. alternifolia made in 1998 by Peter Moore. A Longstock introduction.


  • Flower Colour: Light lilac blue with a pale orange throat
  • Habit: Large, good for a back of a border or as a screen
  • Eventual height: 300 x 300cm (9 x 9ft)
  • Hardiness: Very hardy - 20°C USDA zones 5-9
  • Leaf colour: Greyish green with autumn colour
  • Flowering: June
  • Fragrance: Very fragrant
  • Situation: Sunny to light shade.
  • Wildlife: Attracts early bees and butterflies

Project Details



Place of Origin

alternifolia  China, Tibet

x agathosma Yunnan Provine, China, more info see species

Plant Heritage

Accession Number B191

All details of our collection are held on the main Plant Heritage database including plant name, accession number, date of accession and plant source.


  • Genus Buddleja
  • Cultivar 'Longstock Gem'
  • Category Hardy Hybrid
  • Colours and sizes are approximate and are intended as a guideline, cultivation notes should be followed

Find out more about soil feeding, pruning and pest control.

Cultivation of Plants