Petunia Seeds

the best petunias for containers or the garden

Petunias are native to South America where they were originally discovered in the 18th century. Thanks to the dedication of breeders, what were once lanky plants with simple white flowers now make an excellent bushy and colorful filler for any flower container or garden. These long-lasting annuals now boast a variety of deep purples, bright pinks, and reds, great for attracting pollinators to your garden.

planting petunia seeds

Start seeds inside 10 to 12 weeks before planting outside, after the risk of frost has passed and soil temperatures are around 60°F. Petunia seeds typically require seven to ten days to germinate and do best in consistently moist potting media with temperatures between 70 and 85°F. Petunia seeds are quite small and require light to germinate; sow seeds on the surface of the soil and do not bury. Maintaining high humidity and consistent temperatures will improve germination rates. Try covering your seed-starting container with a humidity dome or plastic wrap and misting regularly. Remove the cover once 10 to 15% of your seeds have germinated and continue misting regularly until most seedlings have emerged.

Petunia seedlings prefer bright light for 12 to 16 hours per day with temperatures around 65°F. Once plants have three sets of true leaves, pot them into lager containers such as plastic cell packs or old single-serving yogurt containers. Harden off plants for a week before transplanting them into the garden.

ideal conditions for your petunias

Petunias prefer full sun but will tolerate light shade, requiring at least five to six hours of light per day to bloom. They are resilient plants that can live in soil lacking rich nutrients but thrive when planted in soils rich in organic matter and/or that are fertilized regularly. Petunias do best in well-drained soils and, when planted in-ground, prefer about an inch of water per week. They don’t mind the heat and are relatively drought resistant, although those planted in hanging baskets and containers require more frequent watering. Plants should be spaced roughly eight to 12 inches apart in the garden and five to eight inches apart in containers and when planted in partially shaded areas. Removing faded or desiccated flowers (known as deadheading) will prevent seed formation and can help prolong blooming. This is a must for petunias planted in containers and will keep in-ground plants looking fresh and healthy.

For more information about planting, growing, and caring for petunia seed, see the Petunia Seeds Planting Guide.