July 2007

Verbena Aztec Series By Camila Valle

The verbena Aztec series from Ball FloraPlant exhibits versatility, performance and color. In commercial greenhouse production, Aztec varieties finish well in var-ious container sizes, from high-density 4-inch pots to 12-inch hanging baskets to mixed containers. Independent university trials have found powdery mildew tolerance in the Aztec series; therefore, less chemical use should be necessary.

Verbena in this series were bred to be uniform and early to flower, and while they should perform well nationwide, the early blooming makes them especially suitable for Southern regions where the spring selling season begins before the start of long days. For home gardeners, Aztec varieties can be used in containers, baskets, landscapes and garden borders where they may grow 8-10 inches tall in full sun.

Aztec verbena cuttings are produced from culture and virus-indexed stock through the Ball Certified Plants program. These varieties are available as both unrooted and rooted cuttings.

Propagation

Choose a well-drained medium with an EC of 0.75-0.80 and a 5.6-6.2 pH. Stick cuttings within 12 hours of arrival. Soil temperature should be maintained at 68-72¡ F until roots are visible. Misting at a high frequency in the initial 36-48 hours should prevent leaf dehydration. As calluses form in 2-3 days, reduce the mist frequency and monitor the mist duration to avoid oversaturated media. Roots should emerge in 5-7 days.

As rooted cuttings are removed from mist (at 7-9 days), apply a broad-spectrum, foliar fungicide spray. Begin fertilization with 75- to 100-ppm nit-rogen when roots become visible and increase to 150- to 200-ppm nitrogen as roots develop.

To improve branching and habit, pinch verbena 18-21 days after sticking. An early B-Nine (daminozide) application may increase the node count below the pinch, promote branching and improve the finished plant habit. Aztec cuttings should be ready for transplanting 24-28 days after sticking.

Growing On

Use a well-drained, disease-free, soilless medium with a pH level between 5.8 and 6.2. Maintain temp-eratures at 62-65¡ F night and 70-80¡ F day. Higher light should increase branching, and warm temperatures may reduce time to flower. While Aztec flowers year round, the shortest crop times will occur under high light and warm temperatures. Plant quality may be enhanced by controlling the temperature in the later crop stages. Aztec varieties were bred to be tolerant of very cool conditions and can be finished outdoors in temperate climates.

During the first 10-14 days, allow the media to dry somewhat between waterings. Avoid extended per-iods of saturated media or wet foliage. Aztec varieties have moderate to heavy fertilizer requirements to promote vigorous growth; use a balanced fertilizer at 200- to 250-ppm nitrogen every watering to ensure maximum growth and flowering. Controlled-release ferti-lizer can be used to supplement a liquid feed program.

Pinching And Finishing

Aztec should be pinched 7-10 days after transplanting. Depending on local production, a second pinch can be applied in propagation for large containers. A Florel (ethephon) application at 300-500 ppm can replace the second pinch. Avoid any application of Florel within eight weeks of sale.

A tank mix of Cycocel (chlormequat chloride) at 750-1,000 ppm and B-Nine at 2,500-3,500ppm may be applied 7-10 days after pinching to encourage a naturally mounded habit. Similar results may occur with B-Nine spray at 3,000-4,000 ppm. A repeat application seven days later may be needed for 4- and 5-inch production.

Aztec verbena were bred to be versatile and well suited to finishing in a range of pot sizes. A 4-inch pot (one plant per pot) will finish in approximately 8-10 weeks from unrooted and 5-7 weeks from rooted cuttings. A 6-inch pot (two plants per pot) should finish in 10-11 weeks from unrooted and 7-8 weeks from rooted cuttings. A 10-inch hanging basket with 3-4 plants per pot should finish in 12-14 weeks from unrooted and 9-11 weeks from rooted cuttings. A 12-inch hanging basket with 4-5 plants per pot will finish approximately in 13-16 weeks from unrooted and 10-13 weeks from rooted cuttings.