How to Grow Trailing Petunias From a Seed

Fill a planter 1 inch from the top with a quality seed starting mixture, available from most specialty gardening stores. Moisten the mixture with warm water, about 80 degrees Fahrenheit, until it drains from the bottom of the container.

Sprinkle the trailing petunia seeds evenly over the soil in the container and press them into its surface with your thumb. Do not cover the seeds with anything, as some varieties require light exposure to respond.

Place the trailing petunia seeds’ planter in a sunny area that maintains temperatures of 80 degrees Fahrenheit or above for most of the day. The trailing petunia seeds’ soil must not fall below 70 degrees Fahrenheit for ideal germination.

Water the seeds daily with warm water, maintaining moist soil until they begin to sprout in about seven to 10 days. The soil must retain a temperature no lower than 70 degrees Fahrenheit throughout the sprouting process. Keep the soil moist and allow the trailing petunias to grow for four to six weeks in their current container.

Prepare the trailing petunia seedlings’ new planters by placing a layer of river rocks on the bottom of each one for drainage. Fill the planters with fertilized potting soil and make several holes, 1 inch apart, in each one.

Scoop groups of petunia seedlings out of their current container with a spoon gently. Place one trailing petunia seedling per hole in each planter. Press the soil lightly around the seedlings to support them. Repeat with the remaining trailing petunia seedlings and prepared containers.

Care for the trailing petunias as they grow per instructions from an expert at your local nursery. Proper care varies by species. Generally, they should receive at least six hours of sunlight per day and you should keep the soil moist.