Grow a Petunia Crop That Dazzles

Stephanie Whitehouse

Consumers are always looking for “What’s new?” every spring, especially in well-established and loved annuals such as petunias. Patterns and unique color markings pique the interest of home gardeners who like to add a little pizazz to their green spaces. The Surprise Sparkle series of petunias from Dümmen Orange are uniquely patterned varieties that have increased in popularity in recent years with their exciting twinkling effect on the petals. The plants have strong vigor, and are ideal for hanging baskets and large containers with their semi-trailing habit.  

Pictured: The Surprise Sparkle Petunia series.

Surprise Sparkle Petunias have recently seen improvement to the consistency in their twinkle patterns throughout the season from cool, early spring to warm early summer. This strong sparkle pattern in an array of bright primary colors is what draws the attention of consumers, plays well with contrasting colors in Confetti Garden combinations and is a conversation starter at any garden party.

Unique Surprise Sparkle Petunias are certainly not like their basic solid-colored sisters. With these vivacious flower patterns comes the need for heightened attention to growing details, so these plants remain snazzy and the center of attention and don’t fizzle flat.

Paying particular attention to temperature and mist levels during the initial stages of propagation ensures successful rooting and sets plants off to a healthy start. Be sure plug trays are grown on benches or floors that are heated to reach soil temperatures between 70 to 75F (21 to 23C), with average air temperatures between 70 to 75F during the day and 68 to 72F (20 to 22C) at night.

Immediately after sticking, water unrooted cuttings uniformly to help “seat” them into the soil media. Good soil-to-cutting contact is important for root establishment. Mist cuttings for the first seven to 10 days, depending upon the season, making sure to keep media moist with mild dry cycles. Once cuttings have callused and established initial roots, water through flood or overhead watering to keep media moist, again with mild dry cycles in between to prevent any disease. Over-misting or delayed mist reduction can lead to slower root establishment and growth, and can lead to iron deficiency.

If you’re a grower who prefers to use chemicals, Florel (3.9% Ethephon) at 250 ppm as soon as cuttings show true roots can be applied in order to stimulate branching and promote uniformity. For those growers who prefer to pinch, rooted liners may be pinched three weeks after sticking to promote the same effect in the branching. Pinched liners will then be ready for transplanting a week later.

Most petunia varieties, regardless of the color or pattern, benefit from a routine feed with added iron and micronutrients. During the misting stage, use a rate of 50 to 75 ppm N. Once the roots are established, rates can be increased to 100 to 150 ppm N. Keep an eye on pH during the liner stage as well, striving for 5.5 to 6, as this will help prevent leaf yellowing.

After transplanting, fertilize at a rate of 200 to 250 ppm N, aiming towards 250 ppm if growing in larger containers and hanging baskets. Again, pH should hover around 5.6 to 6.2 for optimum nutrient uptake.

Surprise Sparkle Petunias are best suited for premium containers and hanging baskets 6 in. and larger.  From a 50-cell liner, Surprise Sparkle Petunias can finish in a 6-in. to 1-gal. premium planter within five to six weeks. For hanging baskets and patio planters 10 in. and above, allow eight to 12 weeks from transplant to retail ready.

If your greenhouse has supplemental lighting, Surprise Sparkle Petunias can benefit, especially for northern and Midwest growers January through early March. Optimal light levels for the perfect sparkle are between 5,000 to 8,000 f.c. (53,800 to 86,100 lux). High light with a negative DIF will help reduce stretching in the plants and will also help increase the amount of “sparkle” seen on the blooms.

Remain consistent in your watering regimen when in the finishing stage with Surprise Sparkle Petunias.  Maintain an even level of moisture in order to prevent root diseases, which can be an issue with overwatered petunias.

Pictured: Close-up of a Surprise Sparkle Red Petunia bloom.

Pinching or the use of PGRs needs to be planned accordingly to optimize branching and rooting. A grower should choose one method that works best for them, but not both. If you’ve pinched in the liner stage, there’s no need to pinch after transplanting. Due to their unique color pattern, Surprise Sparkle Petunias can be sensitive to high-rate PGR applications. Use of PGRs in high rates can distort the finishing habit and delay flowering up to two weeks. Avoid this by applying 500 ppm B-Nine (85% Daminozide) with 750 ppm Cycocel (11.8% Chlormequat) as a tank mix during the liner stage when flower buds aren’t present.

If you’re a grower who wants to help extend the shelf life of finished Surprise Sparkle Petunias at retail, use a Bonzi (0.4% Paclobutrazol) drench at 0.5 to 1 ppm when plants have reached ideal saleable size prior to shipping. This will help ensure your large containers and hanging baskets of Surprise Sparkle Petunias shine bright at retail and for the home gardener.

Paying close attention to these unique patterned petunias from cutting through finished is important. Following these cultural recommendations will help ensure a successful petunia growing season. Adding in a few jazz hands during a crop walk this spring might just add that extra dazzle to your Surprise Sparkle Petunias.

For more information about Surprise Sparkle Petunias from Dümmen Orange North America, and to download our Growing Guides, visit na.dummenorange.com. GT

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Stephanie Whitehouse is Regional Product Manager—Decorative & Heat Loving Annuals for Dümmen Orange–North America. She can be reached at s.whitehouse@dummenorange.com or (614) 813-4829.