Cosmos bipinnatus Double Dutch Rose | Garden Cosmos | Seeds

Cosmos bipinnatus Double Dutch Rose is a tall, elegant garden cosmos with romantic rose-coloured, double to semi-double flowers and delicate, feathery foliage. Part of the Double Dutch series, this variety combines the airy character of traditional cosmos with fuller, more decorative blooms, making it an excellent choice for cut flower gardens, summer borders and landscape planting.

Double Dutch Rose grows to approximately 120 cm tall and flowers from July through October. Its long stems are particularly useful for cutting, while the finely divided foliage adds softness and movement both in the garden and in floral arrangements.

Plant Information

Botanical name: Cosmos bipinnatus
Series: Double Dutch
Variety: Rose
Common name: Garden Cosmos
Family: Asteraceae
Botanical category: Annual
Life cycle: Annual
Plant height: approx. 120 cm (47")
Height category: Tall
Flowering / harvest: July–October
Position: Full sun
Use: Cut flowers, cut foliage and landscaping
Suitable for cutting: Yes

Romantic Rose-Coloured Flowers

Double Dutch Rose produces beautiful rose-pink flowers with a full, layered appearance. The additional petals give the blooms a more romantic and textural character than classic single-flowered cosmos while retaining the natural elegance associated with Cosmos bipinnatus.

The flowers are carried above finely divided green foliage, creating a light and graceful appearance despite the plant's impressive height.

The rose tones are easy to combine in floral work and look particularly beautiful alongside white, blush, burgundy, apricot, lavender and purple flowers.

Tall Cosmos for Cut Flowers

Growing to approximately 120 cm, Double Dutch Rose is particularly well suited to the cut flower garden.

Its tall habit provides useful stems for bouquets and larger floral arrangements, while the delicate foliage can also be incorporated as cut greenery.

Regular cutting encourages plants to continue producing new flowering stems throughout the season.

Double Dutch Rose works beautifully in loose, garden-inspired bouquets where its layered flowers provide a focal point without losing the light, natural character of cosmos.

Flowering from July to October

Double Dutch Rose flowers from July through October, depending on sowing time, climate and growing conditions.

Its long flowering period makes it particularly valuable for summer and early-autumn cut flower production.

Regularly harvesting flowers and removing faded blooms helps prevent unnecessary seed formation and encourages continued flowering.

Sowing

Sow indoors in spring for an earlier start or direct sow outdoors once the soil has warmed and the danger of frost has passed.

For indoor sowing, sow the seeds into a fine, well-drained seed-starting substrate and cover them lightly.

Keep the growing medium evenly moist during germination, but avoid waterlogging.

Once seedlings emerge, provide plenty of light to encourage strong, compact growth.

Cosmos develops relatively quickly, so avoid keeping young plants in small containers for too long.

Planting Out

Plant outdoors once the danger of frost has passed.

Choose a warm, open position in full sun with well-drained soil.

Before transplanting, gradually acclimatise young plants to outdoor conditions.

Allow sufficient spacing between plants to encourage good air circulation and branching.

Growing Conditions

Double Dutch Rose performs best in full sun.

A well-drained soil is ideal. Avoid excessively rich soil and heavy fertilisation, as too much nitrogen can encourage lush foliage growth at the expense of flowering.

Water young plants regularly while they establish. Once established, cosmos can tolerate relatively dry conditions, although consistent moisture during prolonged hot and dry periods supports healthy growth and continued flowering.

Pinching for More Flowering Stems

For cut flower production, young plants can be pinched when approximately 20–30 cm tall.

Removing the central growing tip encourages the plant to branch and can result in a greater number of flowering stems.

Because Double Dutch Rose reaches approximately 120 cm, support may be beneficial, particularly in exposed locations or when plants are grown specifically for long, straight cut-flower stems.

Flower netting or another discreet support system can help protect tall plants from wind and heavy rain.

Harvesting for Cut Flowers

For fresh arrangements, harvest stems when the flowers are beginning to open but are not yet fully mature.

Cutting regularly encourages further flower production.

The long stems and romantic rose-coloured blooms make Double Dutch Rose particularly attractive for garden-style bouquets, seasonal arrangements and mixed cut-flower compositions.

Its fine foliage can also be used to add a soft, airy texture to arrangements.

For Summer Borders and Landscaping

Although particularly valuable as a cut flower, Double Dutch Rose is equally attractive in the garden.

At approximately 120 cm tall, it adds height without creating a heavy appearance. The finely divided foliage allows the plants to blend naturally with neighbouring flowers.

Use it in mixed summer borders, cottage-style gardens, naturalistic planting schemes and dedicated cut flower beds.

Planting several plants together creates a beautiful cloud of rose-coloured flowers from midsummer into autumn.

Easy Annual for a Sunny Garden

Cosmos bipinnatus is an annual, completing its life cycle within one growing season.

Double Dutch Rose combines a tall, graceful habit with an extended flowering period from July to October, making it an excellent seasonal plant for gardens where abundant summer colour and cut flowers are desired.

Its combination of 120 cm height, long stems, delicate foliage and rose-coloured flowers makes it especially useful for creating relaxed, natural-looking plantings.

Cosmos bipinnatus Double Dutch Rose is an excellent choice for growers looking for a tall rose-coloured cosmos for cutting and landscape planting. Its romantic layered blooms, elegant stems and airy foliage provide beautiful material for bouquets while bringing height, movement and abundant colour to the summer garden.