Pronounciation: Pe-TUNE-ya HI-bri-da

Hardiness zones:
Sunset Depends on use
USDA Depends on use

Landscape Use: In Phoenix, garden petunia is a cool season bedding plant used in color borders, landscape drive entryways, hanging baskets, patio containers, or raised planter beds.

Form & Character: Prostrate, formal, showy, bright and cheerful.

Growth Habit: Evergreen, herbaceous, short-lived perennial, somewhat spreading, occasionally reaching a height of 18 inches, often shorter.

Foliage/Texture: Simple and entire leaves are variable in size, mostly ovate, light green to glaucous green, coarsely pubescent, strongly viscid (sticky), stems are also viscid and pubescent; medium texture.

Flowers & Fruits: Flowers are axillary, solitary, sometimes fragrant, funnel form to double ruffled, a myriad of different flower color patterns ranging from white to even black, solid to striped even blotched; fruit inconspicuous.

Seasonal Color: Depends on use and location, but mostly for flower color during winter and early spring color in central Arizona desert landscapes. In contrast, petunia is a short-lived perennial (up to 3 years), in maritime central and southern California landscapes.

Temperature: Garden petunias thrive within a 40^o to 90^oF cardinal temperature range. Flower pigmentation (color intensity) is enhanced within its lower to moderate temperature range and tends to fade as temperatures warm towards and above 90^oF during the spring.

Light: Partial to full sun, no shade.

Soil: Garden petunias prefer an evenly moist and rich garden soil with good drainage characteristics; but they will tolerant some soil alkalinity. However, poor soil drainage and/or excessive soil alkalinity will result in foliar nutrient deficiencies including leaf yellowing and stunted and weak growth.

Watering: Petunias needs regular water to maintain an evenly moist soil especially, especially during years when winter desert rains are sparse (such as the dry La Nina winters of 2017-18, 2020-2021, and 2024-25).

Pruning: Older garden petunia plants can be pruned severely to re-encourage vigor, especially in cooler coastal California climates where they are grown as perennial bedding plants.

Propagation: Sexual (seed) or asexual propagation (softwood cuttings and tissue culture) are used for reproduction of unstable hybrids.

Disease and Pests: There are many including snails, cutworms, tobacco budworm, tobacco mosaic virus, rhizoctonia stem rot.

Additional comments: Garden petunias are great cool season bedding plants for Phoenix mixed flower borders. They are easily bred; there are copious numbers of F₁ hybrids with an amazing array of different flower colors. Plant individuals 12-inches apart, but don't over crowd petunia plants as this will cause plants to become leggy. Some garden petunia varieties can reseed in moist landscape areas. Novel cultivated varieties of different flower colors are released each year. Hybrid trailing selections such as 'Surfina' [a cross between Ruellia humilis (wild petunia) and Petunia x hybrida] are heavy bloomers that are more environmentally stress tolerant, ie. Phoenix friendly.