Aster novi-belgii Alert
Aster 'Alert' photo courtesy of Walters Gardens
Michaelmas Daisies, Fall Asters

Aster 'Alert' is a dwarf selection with double purple-red blossoms. Plants form a bushy clump bearing loads of small daisy flowers. Also known as Fall Asters, these are terrific favourites for autumn colour in the perennial border. The novi-belgii species is valued for its compact growth habit, rich flower colour, and floriferous tendencies. It is native to North America.

  • Height: 30-38 cm (12-15 in)
  • Spread: 30-51 cm (12-20 in)
  • Cold Hardiness: Zone 3-8
  • Sun or Shade: minimum four hours of direct sun
  • Bloom Time: fall
  • Leaf Colour: green
  • Bloom Colour: reddish purple
  • Critter Resistance: deer
  • Nature Attraction: bees and butterflies

Growing and Maintenance Tips

Asters perform best in rich, evenly moist soil and full sun. Give them lots of room to grow; good air circulation will help to prevent powdery mildew. Though this cultivar has a bushy, compact habit, it may still require staking. To promote dense growth that is less likely to flop, pinch plants back from late spring until early July. Plants should be divided every couple of years in the spring to maintain their health and vigour.

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