5. Winter
Petunias are known as an annual, and it’s part of what’s made them one of the most popular choices for flower gardens all over the world – but a lot of new gardeners will take this to mean that the plants can be left alone throughout the whole year, and this can prove to be a fatal mistake if you want to ensure the plant blooms again for next season.
Just because they’re classed as an annual and do well throughout the year in a variety of climates doesn’t mean that you can just leave them be: When the season changes towards winter and colder climates, it’s best to protect petunia bushes from the harsh cold any which way you can – when potted, it might help to bring them inside for the colder mornings; put up protective shade netting when outside.
As a side-note, petunias don’t like wind – plant wind-breaking plants around it where possible, or put up features to block the direct wind.