Petunia × atkinsiana
garden petunia
Hybrid of garden origin; parents from southern South America
Overview
Petunia x atkinsiana is a hybrid grown as a warm-season annual, forming a mounded to trailing plant 6-16 inches (15-40 cm) tall and 12-36 inches (30-90 cm) wide depending on the cultivar group. Stems and oval leaves are soft and sticky with glandular hairs. Funnel-shaped flowers 1.5-4 inches (4-10 cm) across open continuously from late spring until frost; flower color spans white, pink, red, purple, blue, yellow, and bicolor patterns across the many cultivars. This hybrid arose from crosses between Petunia axillaris and Petunia integrifolia. Plants flower heavily in warmth and full sun and slow in cool, cloudy weather. Spent flowers turn to small capsules of numerous tiny seeds. Stems can grow leggy by midsummer without trimming, and rain damages the thin petals of large-flowered types. In frost-free climates the plant persists as a short-lived tender perennial.
Native Range
A hybrid of garden origin not found in the wild. Its parent species, Petunia axillaris and Petunia integrifolia, are native to southern South America, mainly Argentina, Uruguay, and southern Brazil, where they grow in open grassland and disturbed ground.Suggested Uses
Used in containers, hanging baskets, window boxes, and bedding displays, spaced 10-12 inches (25-30 cm) apart. Trailing types are grown to spill over the edges of baskets and walls. The need for frequent watering and feeding in containers and the cold sensitivity limit it to the frost-free part of the year.How to Identify
Appearance
Size & Dimensions
Height6" - 1'4"
Width/Spread1' - 3'
Bloom Information
Flowers open from late spring through the first hard frost in temperate gardens, and nearly year-round in frost-free climates. Bloom is continuous in warm, sunny weather and slows during cool or heavily overcast spells. Removing spent flowers and trimming leggy stems keeps new flowers coming.
Detailed Descriptions
Flower Description
White, pink, red, purple, blue, yellow, or bicolorFoliage Description
GreenGrowing Conditions
Sun Requirements
Requires 6-10 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Water & Climate
Water Needs
Care & Maintenance
Care Guide
Grow in full sun in fertile, well-drained soil or potting mix, with at least six hours of direct sun for full bloom. Water when the top inch (2.5 cm) of soil dries; container plants may need daily water in heat. Feed every 1-2 weeks with a balanced fertilizer, since petunias use heavy nutrients in containers. Pinch or shear leggy stems by one-third in midsummer to renew growth and flowering. Botrytis and root rot develop in cool, wet, crowded conditions. Aphids, budworms, and slugs feed on the soft growth.Pruning
Pinch young plants once or twice to encourage branching. Shear back by about one-third in midsummer when stems grow leggy to bring on a new flush of bloom. Cut off spent flowers and developing seed pods through the season to keep flowering steady.Container Growing
✓ Suitable for container growing
Minimum container size: 2 gallons
✓ Toxicity
Non-toxicPlanting Guide
Planting Methods & Timing
Planting Method
transplant
Indoor Start
10 weeks before last frost
Direct Sow Timing
Started indoors 10-12 weeks before last frost rather than direct sown
Days to Maturity
70–100 days
Plant Spacing
11 inches