Complete Petunia Growing Guide: Varieties, Planting, and Care

Petunias rank among the most popular flowering annuals, offering trumpet-shaped blooms in virtually every color and pattern. Native to South America, modern hybrids descend from crosses between white-flowered Petunia axillaris and violet-flowered P. integrifolia.

Petunia Classifications

Grandiflora: Largest flowers (up to 4 inches), including Merlin Blue Morn, Supercascade, Daddy, and Ultra series.
Hedgiflora (spreading): Low-growing (6 inches) but covering 4 feet—Opera Supreme and Tidal Wave varieties.
Multiflora: Smaller blooms (2 inches) but rain-resistant—Carpet and Surfinia series.
Milliflora: Tiny 1-inch flowers with excellent weather tolerance.

Planting Success

• Timing: Plant after last frost in spring; start seeds 8 weeks earlier indoors
• Light: Minimum 6 hours full sun daily
• Soil: Well-drained, moist peat-based mix with perlite or vermiculite
• Spacing: 12-18 inches in beds; 2-3 plants per container center
• Water/Fertilizer: Regular watering and monthly water-soluble fertilizer (1:4 ratio at planting)

Versatile Applications

Petunias excel in garden beds, containers, window boxes, and hanging baskets. Choose spreading varieties for ground cover, upright types for beds, and trailing forms for containers. Their continuous bloom and easy care make them ideal for beginners and experienced gardeners alike.