Pinch every 14 to 18 days until July 25, again leaving 3 to 5 internodes on each branch which has emerged since the previous pinch. Shears can be used. This will reduce plant height, intensify the dark green color of the foliage, and most importantly create rounder, more uniform plants . A rate of 150 ppm N and K may be sufficient for a soil-based medium. Asters are less salt-tolerant than mums.
Excessive fertilization causes the plants to grow large and tilt in the pots.
Growers need to manage their fertility program to avoid excessive EC build-up or monthly leaching of salts should be practiced. Low fertilization results in small plants. Though asters are more drought tolerant than garden mums, drought stress can cause yellowing of the lower leaves. Fertilization should be terminated when the flowers begin to open to improve flowering longevity. Foliar analysis values for garden aster are provided in Table 1.