How to Grow the Laura Bush Petunia From Seed

Use a cell flat that has about 50 individual cells so you can plant one or two seeds in each cell.

Fill each cell with sphagnum moss. Don’t pack the moss down. Sow the seeds on top of the moss. Petunia seeds need light to germinate and are not covered to germinate.

Use a misting bottle to mist the seed and moss. Do not use a watering can, which will cause the seed to float when watering. The misting bottle will provide moisture to the moss and seed without making the seed move over the moss.

Place the cell flat into a clear plastic bag. This will provide a warm environment and humidity for germination.

Keep the seed tray in a location where the temperatures are between 68 and 85 F. If the temperatures are not ideal, the germination success rate will be low. The area must have bright light, but not direct sunlight.

Continue to keep the moss moist by misting. In 15 to 30 days, the Laura Bush petunia seeds will germinate. When the seeds have sprouted, remove the plastic. Move the cell flat to a location with temperatures about 65 F with bright light. Continue to mist the moss and seedling.

Transplant one seedling into a peat pot when the seedlings have three true leaves. If you have one or more seedlings in a cell, separate the seedlings so each one has a peat pot. Fertilize the seedlings every two weeks with a well-balanced fertilizer diluted in half.

Place the seedlings outside during early spring in a sunny, warm location, but bring the seedlings back inside before night fall. This will help harden off the seedlings so that when it is time to transplant outdoors, the seedlings are ready for the temperature changes. Transplant the seedlings outdoors after the last chance of frost.