Dahlia 'Verrone’s Obsidian'
Dahlia 'Verrone’s Obsidian' is an orchid-form dahlia with starry, near-black blooms and a bright yellow centre. The open shape gives a modern look in the border and can be easier for pollinators to use than densely double dahlias—ideal for a dramatic cutting garden.
For best results, start tubers in pots from March or April in a frost-free place, then plant out once the risk of frost has passed. Choose full sun and a warm, sheltered position, and mix in plenty of garden compost to improve structure and drainage.
Plant tubers about 10–15cm deep with the ‘eye’ facing upwards, spacing plants roughly 45–60cm apart. Keep the soil evenly moist as shoots develop. If you’re growing taller stems or larger flower heads, add a cane early so support is in place before flowering.
Water deeply in dry weather and feed every two to three weeks through summer with a high-potash fertiliser to encourage buds. Deadhead regularly and cut stems often—removing spent blooms helps direct energy into new flowers, giving you a longer, heavier display.
After the first frosts blacken the foliage, cut stems back and lift the tubers to store somewhere cool, dry and frost-free. In very mild areas you can mulch heavily, but lifting is safest. Replant next spring and you’ll usually see stronger plants each year.
| Botanical name | Dahlia 'Verrone’s Obsidian' (Orchid Group) |
| Flower colour | Near-black, starry orchid blooms with a yellow centre |
| Tuber size | Grade I (Top Size) |
| Established height | 90 cm |
| Established spread | 30–60cm |
| Plant spacing | 3–5 per m² |
| Leaf colour | Green |
| Habit | Clump-forming |
| Life cycle | Perennial |
| Hardiness | Half hardy (H3) |
| Years to establish | 1st year |
| Sunlight | Full sun |
| Position | Sheltered |
| Suitable for | Pots, Borders, Cutting garden |
| Soil acidity | Any |
| Soil moisture | Moist but well-drained |
| Soil type | Chalk, Clay, Loam, Sand |
| RHS Award (AGM) | No |
| Growing skill | Easy to grow |
| Pollinator-friendly | Yes |
| Deer resistant | No |
Planting and Flowering Calendar
Key Features
Packed in paper
Packed peat-free
Great for Shade
Attracts wildlife
Perfect for pots
Good for cutting

