Unlike perennials that have short 2-3 week blooming windows, petunias are "long-blooming" plants.
Different types of petunias have slightly different blooming habits: how long do petunias bloom
The duration of petunia blooms depends on several factors, including: Unlike perennials that have short 2-3 week blooming
The most significant factor in bloom duration is gardener intervention. Without care, petunias often stop blooming by mid-summer. petunias often stop blooming by mid-summer.