Dianthus barbatus 'Heart Attack'

Growing and Maintenance Tips:

Thrives in average to medium moisture, a well-drained soil, in full sun. Removing spent flowers will extend the bloom time and pruning in late summer will help maintain its shape. No serious disease and insect issues. 

However, Dianthus barbatus cultivars are usually considered biennial, so as much as deadheading spent blooms will extend flowering time, leaving some late flowers is essential, to ensure survival.