Petunia Seeds,
Rosa Bonheur

Start seeds indoors 8-10 weeks before the last expected frost date in your area. Once the danger of frost has passed and nighttime temperatures are consistently above 50 F, transplant the seedlings outdoors. Petunias grow best in warm temperatures, so make sure to check your local area’s frost date. If you’re not sure how to do that, consult our blog post ‘Our Experts Answer Questions, Share Resources.’

Lightly press the seeds into the soil, but do not cover them, as they need light to germinate. Keep the soil consistently moist and maintain a temperature of 70-85 F for the best germination results. Covering the seed tray with plastic wrap or a humidity dome will help retain moisture. Before planting outdoors, harden the seedlings off by gradually introducing them to outdoor conditions over a period of 7-10 days.

Plant petunias 6-8 inches apart in a location with full sun. Apply a light layer of mulch to help retain soil moisture and suppress weeds. Water about once a week, but avoid overwatering, as soggy soil can lead to root rot. Keep an eye out for common pests like aphids and caterpillars.

• Petunias will readily self-seed in mild winter climates.
• To save seed, hand-pick the brown seed pods.
• Take care to collect the seed pods before they burst and spread the seeds across the garden.
• Store the seeds over winter in a cool, dark, dry place.