Growing Cosmos 'Pinkie' from Seed: A Simple Guide
By The Diggers Club - Australia's No.1 Gardening Club | Published: 2026-10-30
Category: How-to Guides
Learn how to grow Cosmos 'Pinkie' from seed with this straightforward guide. Perfect for beginners, these easy annual flowers bloom all season and attract pollinators.
Quick Answer
Sow Cosmos 'Pinkie' seeds directly in the garden after the last frost, or start them indoors 4–6 weeks earlier. They need full sun and well-drained soil, and they'll reward you with months of pink blooms.
Why Cosmos 'Pinkie' is a Great Choice
Cosmos 'Pinkie' is a mix of delightful pink shades with delicate, daisy-like flowers and feathery foliage. It's easy to grow, drought-tolerant, and blooms profusely throughout the season, making it a favorite for garden beds and borders.
These annual flowers are ideal for beginners because they're forgiving and low-maintenance. They also attract bees and butterflies, adding life to your garden.
When to Plant Cosmos 'Pinkie'
Timing is key. Cosmos are tender annuals, so wait until all danger of frost has passed before sowing outdoors. In most regions, this means late spring. For an earlier start, sow seeds indoors 4–6 weeks before the last expected frost date.
Step-by-Step: Growing Cosmos 'Pinkie' from Seed
- Choose the right time: Sow seeds outdoors after the last frost, or start indoors 4–6 weeks earlier. Check your local frost dates to plan. Sowing too early can result in leggy seedlings or frost damage.
- Prepare the soil: Cosmos prefer well-drained soil. Loosen the top few inches and remove weeds. No rich compost needed—they thrive in average soil. Avoid over-fertilizing, which can lead to more foliage than flowers.
- Sow the seeds: Scatter seeds on the soil surface and press them in lightly, or cover with a thin layer of soil (about 6mm). Space seeds 30cm apart if direct sowing. Don't bury seeds too deep—they need light to germinate.
- Water gently: Keep the soil consistently moist until seedlings emerge, usually within 7–14 days. Use a fine spray to avoid washing seeds away. Overwatering can cause damping off—ensure good drainage.
- Thin seedlings: Once seedlings have two sets of true leaves, thin them to about 30cm apart to give each plant room to grow. Crowded plants produce fewer flowers and are more prone to disease.
- Provide full sun and support: Cosmos need at least 6 hours of direct sun daily. Stake taller plants if needed, especially in windy spots. Insufficient sun leads to leggy growth and fewer blooms.
- Water and deadhead regularly: Water deeply once a week, more in hot weather. Remove faded flowers to encourage continuous blooming. Deadheading extends the flowering season significantly.
Product Spotlight
- Cosmos 'Pinkie': Cosmos 'Pinkie' is a mix of cosmos in delightful shades of pink, with delicate, daisy-like flowers and feathery foliage. It grows to 1.2m and is drought-tolerant. The height and drought tolerance make it perfect for adding a splash of color to borders without constant watering, and the feathery foliage adds texture.
Cosmos 'Pinkie'
