Dahlia merckii (B)
Merck dahlia
A tuberous-rooted perennial to about 2m with many-branched stems and large, divided, mid-green leaves. Single flowers, in summer and autumn, may be pink, purple or white with a purple or yellow centre
Size
Ultimate height
1.5–2.5 metresTime to ultimate height
2–5 yearsUltimate spread
0.5–1 metresGrowing conditions
Moisture
Moist but well–drainedpH
Acid, Alkaline, NeutralColour & scent
| Stem | Flower | Foliage | Fruit | |
| Spring | Green | |||
|---|---|---|---|---|
| Summer | Pink Purple White | Green | ||
| Autumn | Pink Purple White | Green | ||
| Winter |
Position
- Full sun
Aspect
South–facing or West–facing
Exposure
Sheltered Hardiness
H3Botanical details
- Family
- Asteraceae
- Native to GB / Ireland
- No
- Foliage
- Deciduous
- Habit
- Clump forming
- Genus
Dahlia are tuberous rooted perennials with pinnately divided leaves and showy flowerheads, double in many cultivars, in summer and autumn
- Name status
Correct
- Plant range
- Mexico
How to grow
Cultivation
Plant tubers 10-15cm deep in fertile, humus-rich, well-drained soil, in full sun. Cut back to near ground level in mid-autumn. In mild areas, and on well-drained soils, leave the tubers in the ground and protect with a deep, organic mulch. In colder areas, or on heavy soils, lift and store the tubers and replant in late spring after all danger of frost has passed. See dahlia cultivation
Propagation
Propagate by basal softwood cuttings taken in spring from shoots from stored tubers, or divide clumps of tubers ensuring that each division has a viable bud
Suggested planting locations and garden types
- Cottage and informal garden
- Wildlife gardens
- Flower borders and beds
- Cut flowers
- Wall side borders
Pruning
Deadhead to prolong flowering
Pests
May be susceptible to aphids, capsid bug, earwigs, caterpillars, slugs, glasshouse red spider mite and onion thrips
Diseases
May be susceptible to powdery mildews, dahlia mosaic virus, cucumber mosaic virus, tomato spotted wilt virus, storage rots, leafy gall, crown gall, dahlia smut, grey moulds, fungal leaf spot, phytophthora, sclerotinia and verticillium wilts
Get involved
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