Vegetatively produced verbenas are available in two forms. The broad-leaved type, which began with Suntory’s Temari verbenas, are annuals and best suited to patio and balcony plantings. Suntory’s Tapiens have finer foliage and a denser habit, making them ideal as groundcovers. Technical experts from Suntory provide advice on producing verbenas:
Verbenas are day neutral but tend to flower more rapidly under warm temperatures and the long days of spring.
Rooted cuttings should be potted up as soon as possible into 4- to 10-inch pots. Use open, free-draining growing media with a pH of 5.8-6.2 incorporating a balanced fertilizer. Slow-release types can be used per the manufacturer’s recommendations. After potting, the rooted liners should receive a light watering. The crop is best kept on the dry side to aid root development.
Verbenas prefer cool temperatures and high light. Grow plants at 68-75°F during the day and 68-72°F at night. Plants in 4-inch pots are marketable in four to six weeks.
Applications of B-Nine can be used to control growth. Alternatives include pinching and controlling moisture. Pinching is important to achieve a nice, compact, breaking plant. Light and space are important to get the desired habit. Verbena like good amounts of space. If the cutting has received a pinch at propagation, and another one is needed, it is best to pinch at three to four nodes.
Foliage yellowing can occur due to iron chlorosis as a result of high pH or production temperatures that are too cool.
The use of plant growth regulators is very successful in plug production because verbenas will stretch quickly in propagation. B-Nine (daminozide) is most effective for growth control. Apply sprays of 1,500-2,500 ppm 15-20 days after sticking. Florel can be used at rates of 300-500 ppm to encourage auxilary shoots and stop stem elongation.
The crop should be watered uniformly throughout its life using a balanced liquid fertilizer at 200 ppm.
Light levels should be high during production to reduce stretching.
4-inch pots–four to six weeks from liner
6-inch pots–seven to 10 weeks from liner
10-inch pots–12-16 weeks, three liners
4-inch pots–one or two pinches
6-inch pots–two or three pinches
10-inch pots–four pinches
Greenhouse Whiteflies (Trialeurodes
Western Flower Thrips (Franliniella occidentalis)
Red Spider Mite (Tetranychus urticea)
Botrytis cinerea (gray mold)
Thielaviopsis basicola (black root rot)
Powdery Mildew (Oidium sp. and Erysiphe cichoracearum)