The new petunia: thanks to a breeding revolution, these aren't your grandma's flowers

Sunset, June, 2004 by Jim McCausland

Over the last 10 years, the humble petunia has become one exciting flower. Some kinds can now spread color over a 6-foot circle. Others can extend their flower-laden stems from a hanging basket all the way to the ground. Still others can sprout into 2-foot-tall fountains.

[ILLUSTRATION OMITTED]

It's a breeding revolution--all because two Japanese beverage companies, Kirin and Suntory, got into the petunia business. Why would conglomerates better known for beer and whiskey bother with petunias? With plant breeders already on staff, both companies saw the chance to diversify into petunias, which rank among the world's best-selling plants.

Each entered the market with petunias that grew nearly twice as large as any previous variety, inspiring other Asian growers as well as European, Australian, and American cultivators to try to match them. Collectively, these breeding efforts have paid dividends to home gardeners, who can now choose from a wide range of plant forms and flower colors. The chart on page 72 can help you make the right choices.

[ILLUSTRATION OMITTED]

What petunias need

Most gardeners grow petunias as warm-season annuals, planting them anytime after danger of frost is past. In the low and intermediate deserts (Sunset Western Garden Book climate zones 12 and 13), plant petunias in the fall. Choose a series like Jamboree or Supertunia, which can set flower buds during the cool season, when there are fewer daylight hours.

Light. Full sun produces the most blooms. Petunias will take some shade, but the deeper the shade, the fewer the flowers and the more leggy plants will become as they stretch for light.

Soil. Petunias like soil that's rich in organic matter, which also facilitates drainage and retains moisture.

Watering. Never let soil dry out completely. In hot weather, potted plants may need water twice daily.

Feeding. At planting time, fortify the soil with slow-release fertilizer, then feed plants twice a month with a half-strength liquid fertilizer.

Deadheading. You'll get more flowers and longer bloom if you remove faded blossoms. Self-cleaning varieties drop spent flowers naturally.

Pest control. In California, geranium (tobacco) budworm can chew up petunia leaves and buds. The most effective biological control is to spray plants with Bacillus thuringiensis (Bt) at the first sign of damage.

RELATED ARTICLE: Calibrachoa, the petunia look-alike

They look like small petunias, and for years that's what many botanists thought they were. More recently Calibrachoa came to be recognized as a separate genus. This plant spreads and mounds like petunias, but its 1-inch-wide flowers resist the geranium (tobacco) budworms that chew petunias. Since Calibrachoa freely drops its faded flowers, you never have to deadhead. Treat Calibrachoa as a warm-season annual in Sunset climate zones 2-24. However, in mild-winter areas of California (zones 8, 9, 14-24), Calibrachoa can be grown as a perennial (it's hardy to about 23[degrees]).

[ILLUSTRATION OMITTED]

Million Bells, the first series on the market, comes in both trailing and mounding forms. The new Super-bells series has slightly larger blooms in the blue, pink, red, and white range. For warm tones, look for the MiniFamous series.

RELATED ARTICLE: A shopper's guide to petunias

When you shop at nurseries or garden centers, read the plant labels. Even plants within the same series (like Surfinia) come in surprisingly different forms. If the petunias aren't labeled, ask the staff if they can identify the particular series or variety.

For trailing types of petunias, whether they are grown from cuttings or started from seed accounts for certain differences in their appearance, performance, packaging, and price, as you'll note in the chart below.

TYPES &
CHARACTERISTICS    TOP PERFORMERS                  USES & COMMENTS

Trailing.          Cutting-grown: Cascadia,        Grow either kind as a
Cutting-grown      Jamboree, Petitunia,            ground-cover or in a
kinds spread 4-6   Supertunia, and Surfinia        hanging basket.
ft. across. They   series. Jamboree (spreads 3-4   Cutting-grown kinds,
grow so            ft.) is best in the low         sold in 4-in. or
vigorously, you    desert because it blooms well   larger pots, are more
rarely have to     during short winter days.       expensive, but they
deadhead spent     Seed-grown: Avalanche,          fill in and bloom
blossoms.          Ramblin' ('Ramblin' Lilac       more quickly.
Seed-grown kinds   Glo' is shown), and Wave        Seed-grown kinds,
spread 2-5 ft.     series (a four-time All-        sold in multiplant
across.            America Selections winner).     packs, cost less.
Mounding. They     'Easy Wave White', 'Merlin      Grow them like very
grow up, then      Blue Morn' (2003 AAS winner;    low hedges or in
spread out,        shown), Surfinia 'Patio Blue',  large patio
reaching 15-24     'Symphony White', and Tidal     containers. In the
in. high and 1-4   Wave series.                    ground, space them 1
ft. wide.                                          ft. apart for most
                                                   height or 18 in.
                                                   apart for less height
                                                   and more spread.
Grandifloras.      'Limbo Violet', Storm series,   Use them to edge
They bear the      and Ultra series ('Ultra Blue   beds, tuck them in
largest blooms     Star' is shown). 'Limbo         borders, or plant
(3-5 in. wide) in  Violet' (2004 AAS winner)       them in containers or
an array of        grows only 7 in. tall and 1     window boxes so you
colors and         ft. wide and covers itself      can admire their big
patterns,          with 3-in. flowers.             flowers up close.
including
picotees (white
rim, colored
inside), morns
(colored rim,
white inside) and
stars (white
stripes on
contrasting
color).
Multifloras.       Celebrity and Madness series    Use them in exposed
These produce      ('Yellow Madness' is shown).    garden locations,
lots of medium-    Celebrity tolerates foul        where rain or wind
size blooms (2-3   weather well; it comes in       would beat up
in. wide) in the   shades of red, white, and       grandifloras. Tuck
same wide array    blue, as well as other colors.  them in hanging
of colors and      Madness has a wider color       baskets to enjoy
patterns as        range, including perhaps the    their flowers at eye
grandifloras, but  best red of any petunia.        level.
multifloras
recover more
quickly from foul
weather.
Millifloras. They  'Fantasy Pink Morn' (mounding   These self-cleaning
bear a profusion   to 10 in.; shown), Surfinia     flowers look good in
of small flowers   Baby Compact series (mounding   containers and don't
(1 in. wide).      to 2 ft.), and Supertunia Mini  need deadheading. Use
These plants       series (spreads 3-5 ft.).       the mounding kinds to
often have a                                       edge beds.
mounding habit.
Doubles. These     Double Madness series, 'Double  They look best in
have twice as      Wave Lavender', and             containers. Most
many petals as     Reflections series              doubles need
the single-bloom   ('Reflections Purple' is        deadheading,
types listed       shown). Supertunia              especially after
above. Some are    'Priscilla', a semidouble,      rain.
heavily ruffled    doesn't need dead-heading.
like carnations,
others resemble