How Many Petunias Do You Plant in One Hanging Basket?

Varieties

• Petunias include a huge family of hybrids. They generally are categorized into two groups: grandiflora and multiflora. Grandiflora varieties have trailing stems that cascade over the sides of a hanging basket and produce large flowers but relatively fewer flowers than multiflora varieties. Multifloras have a greater quantity of smaller flowers, are more compact and upright plants and tend to be easier to grow with fewer pest problems than grandifloras. A wide variety of color, size and shape options are within both groups, thanks to the many hybrids available.

Spacing

• The number of petunias to plant in a hanging basket depends partly on the size of the petunia variety you choose and the basket's size. In general, however, three to five petunias for a 12-inch diameter basket is a good rule of thumb. One of the most popular hybrid cultivars for planting in hanging baskets is the "Wave" petunia. The Wave petunia website recommends planting no more than three plants in a 10- to 12-inch diameter container, increasing the plant count for a larger container. Planting the petunias closer causes them to compete too much for nutrients. Thompson and Morgan seed company's website recommends planting three trailing petunia plants in a 9-inch diameter basket and five trailing petunias in a 12-inch diameter basket, Some petunia varieties have a very large spread. So reading each plant's label and giving each plant the room it needs to reach its full potential is important.

Water

• Soil in a basket tends to dry out faster than soil in an in-ground flowerbed. That is another reason not to plant petunias too closely; they have to compete for water that is already limited. A basket of plants needs frequent watering, up to twice each day in very hot, dry conditions. You can let the soil dry between watering sessions, but not so much that the plants look wilted. Placing a petunia basket in partial shade reduces the plants' water needs, but full-sun exposure produces more flowers. Good drainage is also key for petunias in a hanging basket. Use a basket with adequate drainage holes to prevent rotten, diseased roots.

Fertilizer

• Vigorous varieties of petunia, such as the "Wave," and double-flowered cultivars should be fed every 10 to 14 days while other varieties can be fed monthly. A properly planted hanging basket and regular feeding keeps petunias from having to compete too heavily for nutrients. Use an all-purpose plant food suitable for flowering annuals, diluting 1 tablespoon of the plant food in 1 gallon of water.