Flower growing guide
Petunias
Petunia x hybrida
Sun
Full sun
Season
Warm
Maturity
60 to 80 days
Water
Moderate
Soil pH
6.0 to 7.0
Spacing
10 to 12 in
Planting petunias
Most gardeners buy starts; seed is tiny and needs 8 to 10 weeks indoors before the last frost. Set plants out after frost risk passes and nights are mild.
Planting details
- Grandiflora types have large blooms; multiflora types weather rain better
- Spacing: 10 to 12 inches
- Pinch leggy starts at planting for bushier growth
Growing requirements
Petunias want full sun and fertile, well-drained soil. Containers need regular watering and feeding; in-ground plants are more forgiving.
Harvesting and care
Deadhead older varieties to extend bloom; many modern hybrids self-clean. Shear leggy stems by a third in midsummer to trigger a fresh flush.
Common mistakes
- Underfeeding container plants, which run out of nutrients by midsummer
- Shade, which reduces flowering to a trickle
- Letting stems get long and stringy before trimming them back
Companion plants
Petunias edge sunny beds and fill containers alongside trailing lobelia or upright salvia without heavy competition.