How To Grow Aster Flowers From Seed

Aster flowers are such a productive annual to grow. These fluffy blooms are a popular choice if wanting to grow cut flowers. They can be started off once all risks of frosts have passed in early spring.

Happy sowing,


Types of Aster Callistephus chinensis:

King Size - large double and semi double blooms, petals only have a slight curl.

Tower - peony like, petals turn inwards.

Matsumoto - pom pom, very uniform. 

Unicum - needle like blooms. 

Sowing + Germination Tips: 

  • Establishing plants early will help avoid short stems.
  • Raise seedling in a greenhouse, sow the seeds 3mm deep into punnets. Germination should occur between 10-14 days.
  • Grow seedlings at 21-22 degrees. 
  • Avoid seedlings becoming root bound, up the size of the punnet if needed.

Planting Tips:

  • Harden off the plants before planting them in the ground outside. Making sure any risks of frosts have past before this process and before transferring to the garden.
  • Asters prefer a full sun position with well draining soil.
  • Space the seedlings 30cm apart.
  • As they can grow up to 75cm, we recommend supporting them with flower netting to avoid damage in high winds and help produce straight stems. 

Harvesting Tips:

  • Harvest when in the cooler parts of the day, early morning or later evening and when the bottom ray florets of the flowers have just opened.
  • Seed to bloom takes around 110 days.
  • Vase life 7-10 days. 

We have 15 wonderful varieties for you to try at home. View our Aster Flower Seed collection here.

Check our climate chart to see when you can pop them in the ground.

Aster China Matsumoto Apricot

Aster King Size Appleblossom

Note the flower netting support on these aster flower, keeping them supported from wind and helping with straight stems.

View our Aster Flower Seed collection here.