About
Smyrnium perfoliatum, perfoliate alexanders, is an upright biennial with stout, ribbed stems, green, broadly divided basal leaves to 20 cm and shorter, bright, yellow-green upper leaves joined around the stem, topped with open sprays of tiny, yellow-green flowers in the second spring. A rewarding and architecturally striking biennial for a shaded or semi-shaded wild garden.
About the genus
Smyrnium are erect, branching biennials producing broadly oblong, divided lower leaves and rounded upper leaves with branched umbels of small, greenish-yellow flowers in late spring and early summer. Rewarding plants for a wild or informal garden.
Plant details
Plant typeAnnual Biennial
HabitBushy
FoliageDeciduous
Height1-1.5 metres
Spread0.5-1 metres
Time to full height1-2 years
Suggested usesBorders, containers, mixed plantings.
Native toEurope, N Africa, Turkey, Caucasus
Care notes
CultivationThis plant is listed on Schedule 9 of the UK Wildlife & Countryside Act as an invasive non-native species. Although not banned from sale, it is an offence to plant or cause these to grow in the wild IN ENGLAND AND WALES. Gardeners possessing them should undertake measures to control them. See RHS advice on invasive non-native species for further information
PruningMinimal pruning required. Remove dead or damaged growth as needed.
PropagationPlease see cultivation notes
Pest resistanceGenerally trouble-free. Monitor for slugs and aphids.
Disease resistanceGenerally disease-resistant. Ensure good air circulation.