How To Grow Aster Flowers From Seed

Aster (Callistephus chinensis) 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 and can be sown until December in most Australian climates.

Types of aster flowers

Sowing and germination tips

Planting and harvesting tips

Our favourite asters


Types of Aster:


King Size

Large double and semi double blooms, petals only have a slight curl.


Lady Coral
Smaller compact blooms, tightly packed petal.


Tower
Peony like, petals turn inwards.


Matsumoto
Pom pom, very uniform. 


Unicum
Needle like blooms. 


Starlight
Needle like blooms.


Chrisantella
An amazing new range of asters in the most wonderful array of pastel colours, the premium aster.

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

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. 

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

Some of our fave Asters