Clematis 'Lagoon'

Clematis macropetala 'Lagoon' comes from the English nursery George Jackman & Son and was named in 1959. It is a selection of Clematis macropetala, and its name has a little history: the name 'Lagoon' had previously been given to another Jackman seedling, which was renamed 'Maidwell Hall' in 1959. The nodding, bell-shaped flowers measure 6-8 cm and glow in deep blue to violet-blue; inside sit yellowish-white staminodes that give the tepals a soft contrast.

'Lagoon' flowers from April to May on the previous year's wood. Growing to about 300 cm, it clothes trellises, fences and pergolas and can also be grown in a large container. It thrives from full sun to partial shade and tolerates any aspect – what matters is moist, well-drained soil in which the root area stays cool and shaded.

The variety is very hardy (zone 5, down to about -28 °C) and has been awarded the RHS Award of Garden Merit. For vigorous growth and plentiful flowers the following year, cut 'Lagoon' back to about 100 cm in June. Plant it 5-8 cm deeper than it stood in its pot – this encourages strong new shoots from the base.