Space Plants Generously
When growing in mass, it’s tempting to plant petunias close together for quick coverage—but overcrowding leads to airflow problems, more disease, and weaker growth. Even Wave petunias need about 12 to 18 inches between plants to really spread and thrive.
Proper spacing also makes it easier for beneficial insects to move through the foliage and for you to reach in to deadhead or water. I like to stagger rows in a zigzag pattern for even coverage and to reduce gaps between plants as they mature. It’s worth the planning upfront for a healthier, more uniform floral display!