Dahlia 'Opal' (Ba) — Bushy, clump-forming, tuberous perennial

Overview

Dahlia 'Opal' (Ba) is a bushy, clump-forming, tuberous perennial bedding in the genus Dahlia, part of the Asteraceae family, with green, occasionally dark-leaved foliage. Dahlia 'Opal' (Ba) grows best in full sun, and tolerates loam soils and neutral pH. Its UK hardiness is rated H4. Suggested uses include borders, containers and cut flowers.

About

Dahlia 'Opal' is a clump-forming, tuberous herbaceous perennial grown for a long flowering run from July to October. It forms well-branched clumps with green, sometimes darker, foliage and suits formal borders and containers. Plant in a south-facing, sheltered spot in neutral loam kept moist but well drained. It is classed H4 for UK hardiness, making it suitable for many gardens where summers are warm enough for reliable flowering.

About the genus

Dahlias come from the high meadows of Mexico, and somewhere in that heritage is the explanation for how they behave here: tender to frost, hungry, generous beyond all reason. No other plant gives you quite so much for so little. One tuber, planted after the last frost, becomes a shrub's worth of flowers by August — and the more you cut, the more they come.The range is faintly ridiculous. Tight pompoms, spiky cactus types, singles the bees adore, dinner-plates the size of your face. Whatever your garden's mood, there is a dahlia that agrees with it, which is probably why every generation falls out of love with them and then, a decade later, falls straight back in.They're at their best when much of the garden is winding down — late summer into autumn, flowering hard until the first frost calls time. I think of them as the encore. And they always play it.

Written by Henry

In the garden

Dahlia 'Opal' is a bedding-type, herbaceous perennial raised for its extended display of blooms from July to October. The plant produces multi-stemmed clumps from tubers, carrying green leaves that can occasionally be darker on some cultivars. Positioning should favour full sun and a south-facing aspect so the canopy receives maximum light. Soil should be loam of neutral pH, retained evenly moist yet allowed to drain; this cultivar does not suit waterlogged conditions. A sheltered site reduces wind exposure and helps stems remain upright through the flowering season. Hardiness is H4 (average), so the variety is appropriate for many parts of the UK without extreme winter protection measures. Use Dahlia 'Opal' where its long July-to-October bloom period will be appreciated: mixed borders, container plantings or as a source of cut flowers. Its clump-forming habit fills a planting quickly, and the combination of a south-facing position and moist, well-drained neutral loam gives the best chance of a consistently productive season.