Aster, Michaelmas Daisy:
Recommendations for Maintaining Postharvest Quality
Produce Facts in English > Aster
Michael S. Reid
Department of Plant Sciences, University of California, Davis
Aster spp. The family Asteraceae, and the genus Aster include numerous species and cultivars used in horticulture. A. ericoides ‘Monte Casino’ is particularly important in the florist trade. Another important aster for florists is the China aster, Callistephus chinensis.
As with most members of the Asteraceae, immature flowers (ones harvested too early) will generally not open properly. Purchase as you would purchase chrysanthemums, more open (at least three-quarters open) than in a bud stage. Avoid specimens with yellowing leaves’ as this is an indication of improper storage and/or growing conditions.
Grading and Bunching
There are no grade standards as such, apart from the standard quality attributes of stem length, foliage quality, uniformity, and freedom from defects. Depending on the species and cultivar, bunches may be prepared by stem number (China aster, for example) or by bunch size (‘Monte Casino’ aster, for example).
Members of the Asteraceae are generally unaffected by exposure to moderate concentrations of ethylene.
Poor water relations often limit the vase-life of asters. This can be demonstrated by wilting of the flower and/or buds. Their vase life has been shown to be extended by a 10-second pretreatment with high concentrations (1000 ppm) of silver nitrate, which is a very effective germicide.
Store asters at 0-1ºC.
Asters are packed in traditional flower boxes, hampers, or Proconas.
It is very difficult to make broad flower care recommendations for asters because of the large number of species and cultivars. Keep stems and vase solution clean. It is especially important with asters to remove leaves that might be in the water since bacteria grow quickly on leaves that are under water, contaminating the vase solution and leading to early wilting. Treat with a hydrating solution and prepare the preservative solution properly to minimize contamination by debris and microorganisms.
First published on this website: October 2004