[header] How to grow petunias [title] Pick your type of petunia. [step] Although there are hundreds of named petunias, they tend to fall into four basic categories, which are determined by flower size and growth habit. Some of these types of petunias work better being grown in a container, while some are better suited to the garden. 
[substeps] Grandiflora have the largest flowers and are the most commonly-used type of petunia. Some have single blooms while others are doubles and are available in both upright and cascading varieties.