Petunias are one of the most popular flowering annuals. There are many varieties of petunias, all of which fall into one of four categories, according to the University of Minnesota Extension Agriculture department.

Categories are grandiflora, with large flowers 3 to 4 inches across; multiflora, smaller, but with more individual blooms; milliflora, smaller and more plentiful still; and groundflora, or spreading petunia, which can cover a large area over a growing season.

Petunias can be a bit finicky in cold weather, so it's advisable to wait until all frost warnings for the season have ended before planting them.

Diane Young, an employee at The Barn Nursery, offered some tips for planting and caring for petunias.

five tips

1. Petunias can be planted in the ground or in pots. Just make sure they have fresh soil.
2. Pinch plants back to encourage branching. This means to pluck drooping blossoms or scraggly stems to let the other flowers grow healthily. Think of it along the lines of trimming split ends.
3. Don't worry if some buds haven't opened as soon as the others; they'll grow and open at their own pace. "The tighter the bud, the longer it is to open," said Barn Nursery employee Diane Young. She noted there's really no way to ensure all buds will open at the same time.
4. Petunias will tolerate a light frost but not a freeze. If heavy winter weather returns, be prepared to hold a floral funeral. Young recommends planting them after April 15.
5. Plant them in a location with plenty of light.