Cosmos Fizzy Rose

Cosmos bipinnatus 'Fizzy Rose' Cosmos 'Fizzy Rose'

Soft, semi-double pale mauve petals delicately etched in a deeper shade at the edges — creating a subtle picotee effect — on tall airy stems above feathery Cosmos foliage. 'Fizzy Rose' is the refined, vintage-romantic Cosmos for gardeners who find traditional pink Cosmos too bright and want something distinctly more sophisticated.

While most Cosmos flowers are uniformly coloured, 'Fizzy Rose' produces semi-double blooms in soft pale mauve-pink with each petal subtly outlined in a slightly deeper shade — the picotee effect that gives the variety its quietly elegant character. The result is a flower that reads as antique romance rather than carnival cheer, perfectly suited to vintage-themed plantings, soft pastel cottage borders, and refined wedding flowers. Tall on airy stems (90–120cm), with characteristic Cosmos feathery foliage. Half-hardy annual flowering July through October. RHS Plants for Pollinators recognised — the semi-double form still allows pollinator access to the central nectar (unlike fully double Cosmos varieties). One of the most refined Cosmos in cultivation.

A note on growing

The Cosmos "starvation rule" is essential: do not feed. In rich soil or with nitrogen fertiliser, 'Fizzy Rose' produces lush foliage and few flowers. In poor, lean, dry, unfed ground in full sun, it flowers prolifically. Plant in the leanest, sunniest position you have.

Sow indoors from mid-April at 18–22°C (slightly later than other Cosmos varieties as it's particularly frost-sensitive). Surface-sow as the seeds need light to germinate. Germination 7–14 days. Pot on and harden off carefully. Plant out only after all risk of frost has passed (late May/early June) in full sun. Pinch out the growing tip at 15–20cm to encourage bushy growth and more cutting stems. Deadhead or cut regularly for continuous flowering.

Where it shines

In refined pastel cottage borders, where the soft mauve picotee adds genuine elegance to the planting. As a cut flower for vintage-romantic and wedding arrangements — the soft picotee detail elevates simple bouquets into something that looks designed. In moon gardens and evening borders, where the pale colour reads beautifully in low light. In wildlife gardens, where the semi-double form is more accessible to pollinators than fully double Cosmos varieties.

Plant alongside

For a sophisticated vintage cutting scheme, combine 'Fizzy Rose' with the white-and-blush ombré of Cosmos 'Daydream', the cool indigo of Clary Sage 'Oxford Blue', and Ammi majus for airy white. In cottage borders, pair with Cornflower 'Mauve Boy' (matching mauve tones) and Achillea 'Pastel Mixed' for a coordinated romantic scheme.