Tips on Planting Petunia Flowers

Planting Time

• Plant petunias in the garden bed once all frost danger is past in spring. While mature plants may tolerate light frosts, seedlings are killed by cold temperatures. If starting the seeds yourself indoors, sow them eight to 10 weeks before the last expected spring frost in your area. Nursery petunias are available all throughout summer and can be planted any time between the last spring frost and late summer.

Site Selection

• Petunias thrive in full sunlight. Place them in an area that receives all-day light or at least full morning light and partial afternoon shade. The plants require well-drained soil, as they don't tolerate wet roots. Adding compost and other organic material to the soil prior to planting improves the nutrient and moisture quality of the soil.

Hardening Off

• Harden-off petunias before planting them outdoors. Set the petunias out in an area protected from wind and sun for a few hours one week prior to transplanting. Leave the plants out a little longer each day. By the end of the week they should be out for a full 24 hours and be ready for transplant. This process helps the petunias acclimate to outdoor conditions and makes them less prone to transplant shock.

Transplanting

• Plant the petunias in the bed in afternoon or anytime during a cloudy day. The minimal sunlight helps the petunias adjust to their new home without suffering heat or sun shock. When planting, set the petunias in the bed at the same depth they were growing at in their seedling pots. The portion of the plant where the stems emerge from the roots, called the crown, should sit right at or slightly above soil level.