Petunia Hybrids

Fundamental Facts

HARDINESS: Frost tolerant
PREFERRED SOIL pH: Adaptable
PREFERRED SOIL TYPE: Moist, well-drained
PREFERRED LIGHT: Sun
ATTRIBUTES: Trailing plants covered with colorful flowers from June until frost; for beds, pots, or baskets
SEASON OF INTEREST: Early summer to fall
FAVORITES: Ground-hugging 'Purple Wave', trailing 'Misty Lilac Wave'; 'Madness' or 'Primetime', double-flowered 'Burpee's Best'
QUIRKS: Retains spent flowers: trim to promote flowering
GOOD NEIGHBORS: Verbena, fan flower, roses, zonal geraniums
WHERE IT GROWS BEST: Full sun, moist soil
POTENTIAL PROBLEMS: Viruses
CRITTER RESISTANCE: Good
SOURCE: Seeds, bedding plants
DIMENSIONS: 6-8 in (15.2-20.3 cm) tall; stems cascade 1-3 ft (0.3-1 m), depending on variety

Petunia in the Landscape

Pretty petunias seem to be everywhere in summer, spilling over the sides of window boxes, containers, and hanging baskets, and brightening garden beds with their rainbow colors and trumpet-shaped flowers. In fact, few flowers come in the color range that petunias boast. Petunia blossoms can be pink, scarlet, red. white, blue, purple, or yellow. Some are subtly pastel, others are brazenly bright. They can be striped, streaked, or enhanced by a contrasting central white "star" in the throat. Some varieties have double flowers with a fluff of petals in the center, while traditional types are single-flowered. Evening fragrance is often another virtue. Petunias are such strong summer bloomers that they're sometimes thought overused in the garden, but why resist a flower that grows so easily and always delivers?

Keeping Up With the Flowers

Petunias are such steadfast performers that the biggest challenge is keeping abreast of the comings and goings of their flowers. Petunias don't drop their flowers after they fade; instead you need to keep them tidy. At least once a week, more often if possible, clip off the dead blooms to keep them looking neat and to encourage new flowers. Petunias often will bloom themselves ragged by midsummer, but you can easily help them make a comeback by clipping old stems back to 6 in (15 cm) in length, and then applying a soluble high-phosphorus "bloom-booster" formula fertilizer.

The Best Petunias

There are so many petunias on the market, it's difficult to choose the best. Supertunias and the Surfinia series are such vigorous performers that they blossom continually through the summer. Supertunias are reputed to grow an inch (2.5 cm) a day to cover ground quickly and give a nearly instant show. Especially heat-and drought-tolerant varieties with a broad range of colors include 'Madness', 'Primetime', and 'Celebrity'. If you want yellow flowers, try 'Prism Sunshine'. If you find the flowers of the doubles intriguing, go for 'Burpee's Best'. For vivid pink and purple petunia blooms galore, the Wave series are hard to beat. Petite 'Fantasy' petunias make lacy-looking, compact edging plants.

Increasing the Bounty

In spring and early summer, petunias are readily and inexpensively available as bedding plants at garden centers, discount stores, and supermarkets. And some of the most vigorous petunias are propagated from cuttings and only sold as bedding plants. But if you like to start seeds, sow petunia seeds indoors 10-12 weeks before your last frost date. Sprinkle the super-fine, powderlike seeds over the top of moistened commercial seed-starting soil, and don't cover them. Keep the soil moist and place the container in a sunny, warm place at 70 -80 F (21-26*C) for 2 weeks.

After sprouting, grow seedlings in a sunny, 60°F (16°C) place (preferably a greenhouse or under grow lights). In 4 to 6 weeks you can transplant the seedlings into pots and continue to grow them in a sunny place until planting outdoors after danger of frost is past. Petunias are generally trouble free. If smooth-edged holes appear in leaves and flowers suspect slugs. Place shallow saucers of beer (slugs crawl in and drown) among plants in the evening to dispense with these night-feeding pests. Petunias are sometimes affected by incurable viruses. If leaves begin to wilt or brown on well-watered plants, destroy and replace affected plants.