June 2009 Culture

Veronica x hybrida ‘Christy’ By Paul Pilon

Veronica 'Christy' is a recent introduction that offers growers many desirable attributes such as a compact growing habit, extended bloom time and ease of production. Washington plantswoman Christy Hensler bred 'Christy' by crossing Veronica 'Crater Lake Blue' with Veronica prostrata.

'Christy' forms low, attractive mounds of decorative highly serrated, fernlike foliage reaching a manageable 6-9 inches high and 16 inches across. The plant becomes covered with short flower spikes in late spring, and blooming continues sporadically throughout the summer and into the fall. The small- to medium-size blue-violet blooms have an attractive tiny white eye. If flowering wanes during the heat of the summer, the plants can be trimmed back to reinvigorate growth and flowering.

Speedwell can be easily grown in average, medium wet, well-drained soils in locations with full sun across USDA Hardiness Zones 5 to 9. During the heat of the summer, particularly in Southern locations, it performs best when grown under partial shade. In the landscape, 'Christy' is ideal for border or mass plantings, in rock gardens or along walkways, and for patio planters.

With its compact habit, early bloom time and spectacular display of color, 'Christy' is well suited from commercial production in small container sizes and marketed alongside bedding plants.

Propagation

'Christy' is vegetatively propagated by tip cuttings by licensed propagators. Before sticking the unrooted cuttings, moisten the rooting medium in the liner tray. Rooting compounds are optional as Veronica will root well without using them.

Place the cuttings under a low misting regime for the first six to 10 days of propagation. When possible, propagate under high humidity levels (90 percent relative humidity) with minimal misting. Seven to 10 days after sticking, apply water-soluble fertilizers using 75- to 100-ppm nitrogen at each irrigation. The misting can gradually be reduced as the cuttings form callus and root primordia; overmisting will lead to disease problems. Remove the cuttings from the mist once they are rooted. The cuttings are usually rooted in less than three weeks with soil temperatures ranging from 64-68¡ F. Liners take five to seven weeks from sticking to become fully rooted and ready for transplanting.

Production

When transplanting liners, plant 'Christy' even with the soil line of the plug it was previously produced in. It performs best in a slightly dry to moist, well-drained growing mix. Speedwell requires an average amount of irrigation. When irrigation is necessary, water them thoroughly then allowing the soil to dry slightly between irrigations.

Veronica is a moderate feeder. Maintain the media throughout the production cycle with a slightly acidic pH between 5.5 and 6.2. Nutrients are commonly delivered using water-soluble sources, providing 75-100 ppm using a constant liquid fertilizer program or 150 ppm as needed. Several growers incorporate low rates of controlled-release fertilizers (0.75 to 1 pound of elemental nitrogen) into the growing mix before planting to effectively provide nutrients to containerized Veronica.

Given its compact habit, it is usually not necessary to control stem elongation during production. Under certain growing conditions or under high plant densities, it may be necessary, although not common, to use chemical plant growth regulators. A single foliar application of uniconazole (Concise or Sumagic) at 5 ppm or paclobutrazol (Bonzi, Paczol or Piccolo) at 30 ppm should provide effective control of stem elongation.

Insects and Diseases

Although Veronica can be produced relatively free of diseases and insects, growers frequently observe root rots and aphids during production. Botrytis, powdery mildew, thrips and whiteflies may also be observed on occasion. Root rots can commonly be avoided with good irrigation practices (avoid continuously saturated conditions) and keeping the EC in the root zone below 2.5. Insects and diseases can be detected with routine crop monitoring; control strategies may not be necessary unless scouting activities indicate actions should be taken.

Forcing

Veronica 'Christy' is easy to produce into bloom for spring sales.

It has an obligate cold requirement for flowering. Vernalize them in the final container or as large plugs (21-cell or larger) for nine to 12 weeks below 41¡ F. After vernalization, they can be grown at any day length, as they are day-neutral plants. The length of the photoperiod has no effect on the time to flower or the number of blooms produced. The time to bloom after vernalization is a function temperature. 'Christy' grown at 65¡ F will take approximately eight weeks to reach flowering. Producing them at cooler temperatures increases the time to flower but will improve the overall quality characteristics of the plant, such as the color intensity of the foliage and flowers.

To obtain full, flowering plants for spring sales, plant them during the late summer of the previous season. Transplant plugs into the desired container during mid- to late August, bulk them up before winter, overwinter them and force them to bloom in the early spring. This will result in fuller, more colorful plants when they bloom.

Availability

Veronica 'Christy' is brought to the marketplace by Plant Haven, Inc. (www.planthaven.com) located in Santa Barbara, Calif. Rooted liners are available exclusively from Ball Horticultural Company (www.ballhort.com) and its licensed propagators. Finished containers may be purchased from many reputable companies across the country.