Petunia Seeds,
Superbissima Giant Alba

Start petunia seeds indoors 8-10 weeks before the last expected frost to get an early bloom. Transplant seedlings outdoors only once all danger of frost has passed and nighttime temperatures remain above 50 F. In warmer regions, petunias can also be directly sown into the garden in early spring or fall. Learn about your area’s hardiness zones and first/last frost dates in our blog post ‘Our Experts Answer Questions, Share Resources.’

Sow seeds on the surface of moist soil—they require light to germinate, so do not cover them with soil. Maintain a temperature of 70-85 F for best germination, which usually takes 7-14 days. Keep the soil consistently moist but not waterlogged. Once seedlings have developed several true leaves, transplant them into larger containers or directly into the garden, spacing them 10-12 inches apart to give room for their large blooms.

Water petunias about once a week and avoid overwatering to prevent root rot. Fertilize with a balanced liquid fertilizer every 2-3 weeks to encourage more flowers. If plants become leggy, trim them back by one-third to encourage fresh growth. In extremely hot climates, petunias may slow blooming, but providing light afternoon shade can help reduce heat stress. Removing spent flowers and occasional light pruning will keep the plant looking full.

• 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.