Flower diameter — China aster

To evaluate inflorescence diameter, a methodology measuring the maximum linear dimension during the full bloom phase is used. Trait values range from small forms (2.5–3 cm) to large specimens reaching 16–18 cm. Measurements are conducted in accordance with variety testing protocols for the identification and grouping of cultivars by structure type and plant habit.

This trait directly determines the crop's application: large-flowered varieties (10–15+ cm) are primarily grown for cut flowers, whereas small-flowered ones (2–8 cm) are more frequently used in landscape design. There is a correlative relationship between inflorescence size and shoot count: varieties with the largest flowers typically form fewer inflorescences per plant than small-flowered forms. In professional floriculture, agronomists regulate inflorescence diameter through disbudding and controlling the number of shoots.