About
Dahlia 'Alstergruss' is a tuberous perennial that grows in dense clumps and reaches a height of approximately 45 cm. It features serrated leaves that are dark green in color. From midsummer to autumn, this plant showcases large orange blooms, each adorned with a creamy-white collarette and a yellow center, all held on sturdy, upright stems.
About the genus
Dahlias are perennial plants with tuberous roots, characterized by their finely dissected leaves and prominent flowerheads. Many varieties feature double blooms, which appear during the summer and fall seasons.
Growing conditions
- Sunlight
- Full sun
- Soil type
- Clay, Loam, Sand
- Soil pH
- Acid, Alkaline, Neutral
- Soil moisture
- Moist but well-drained, Well-drained
- Aspect
- South-facing, West-facing
- Exposure
- Sheltered
- UK hardiness
- H3
Plant details
- Plant type
- Bedding, Herbaceous Perennial
- Habit
- Clump forming
- Foliage
- Deciduous
- Height
- 0.1-0.5 metres
- Spread
- 0.1-0.5 metres
- Time to full height
- 1-2 years
- Suggested uses
- City and courtyard gardens, Cottage and informal garden, Patio and container plants
Care notes
- Cultivation
- Grow in fertile, humus-rich, moist but well-drained soil, in full sun. Pinch out growing tips to encourage bushy plants and stake taller dahlias, see staking perennials. Water in dry periods if needed. Lift and store tubers in autumn to replant, or use as a source of cuttings, in spring. See dahlia cultivation, and our video How to plant dahlia tubers and care tips
- Pruning
- Deadhead spent flowers to encourage further flowering. Cut back to near ground level in autumn, before lifting and storing for the winter
- Propagation
- Propagate by softwood cuttings taken in spring from shoots from stored tubers, or divide the tubers ensuring each division has a viable bud
- Pest resistance
- May be susceptible to aphids, leaf miners, glasshouse red spider mite and slugs. Earwigs sometimes damage blooms. Capsid bug and caterpillars are occasional pests
- Disease resistance
- May be susceptible to Powdery mildews in dry conditions. In wet weather grey moulds and other fungal rots can be a problem. Fungal rots can also damage stored tubers. A virus may cause stunting, leaf markings and distortion