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Petunia
Petunia ×atkinsiana
Overview
The world's most popular bedding annual, petunias have been bred into an incredible variety of forms — from classic trumpets to ruffled doubles, tiny spreading groundcovers, and trailing cascades for hanging baskets. Their South American wild ancestors were modest plants, but centuries of breeding have produced flowers in virtually every color with patterns including stars, veins, and picotee edges.
Growing Conditions
How to Grow Petunia
Petunia (Petunia ×atkinsiana) is a forb/herb that grows to about 5 feet tall and 4 feet wide.
Petunia is hardy across USDA hardiness zones 7–11. Plant it in rich, well-drained soil or potting mix, at a slightly acidic pH of 6–7.5.
Exact sowing, transplanting, and harvest months shift by climate zone — the planting calendar below lays them out for cool through hot regions. Its flowers appear from June through October, offering moderate value to pollinators. The details above are a starting point — your ground will teach you the rest.
Companion Planting & Soil
Petunia grows well alongside alyssum, marigold, geranium, and dusty miller.
Good Companions
Planting Calendar
When to sow, transplant, and harvest by growing zone.
| Zone | Action | Months | Notes |
|---|---|---|---|
| Cold (1-2) | Start Indoors | Mar — Apr | Start indoors 8-10 weeks before last frost; tiny seeds need light — do not cover |
| Cold (1-2) | Transplant | Jun — Jun | Transplant after all frost danger; pinch young plants for bushiness |
| Cold (1-2) | Bloom | Jun — Sep | Blooms until first frost; deadhead or shear back midseason if leggy |
| Cool (3-4) | Start Indoors | Feb — Mar | Start indoors 10 weeks early; surface sow |
| Cool (3-4) | Transplant | May — May | Transplant after last frost; trail types great for hanging baskets |
| Cool (3-4) | Bloom | May — Oct | Long bloom; cut back by half in midsummer for fall flush |
| Moderate (5-7) | Transplant | Apr — May | Transplant in spring; feed every 2 weeks for continuous bloom |
| Moderate (5-7) | Bloom | Apr — Oct | Continuous bloom spring through fall; feed regularly |
| Warm (8-9) | Transplant | Mar — Apr | Plant in spring; may fade in summer heat — cut back and refeed |
| Warm (8-9) | Bloom | Mar — May | Spring bloom; cut back in summer heat; rebloom in fall |
| Warm (8-9) | Bloom | Sep — Nov | Fall rebloom after cutback |
| Hot (10+) | Transplant | Feb — Mar | Plant in early spring; or fall through winter as cool-season annual |
| Hot (10+) | Bloom | Oct — Apr (wraps) | Bloom fall through spring; treat as cool-season annual |
Uses
Beyond the Garden
Petunia earns its keep past the plate, too: most popular bedding annual worldwide; hanging baskets and window box staple; continuous bloom from spring through frost.
