April 2012 Culture, Variety Info

Perennial Solutions: Gerbera Garvinea Series By Paul Pilon

In recent years, gerbera has become increasingly popular in the bedding plant and indoor potted plant industries. Gerbera produces an abundance of cheerful daisy-like flowers consisting of numerous vibrant flower colorations. In the past, numerous cultivars of Gerbera jamesonii were used; however, these cultivars have many soft characteristics lending them susceptible to plant pathogens and not suitable for long term and carefree use in landscapes.

Recently, breeding efforts by the gerbera breeding company Florist Holland from the Netherlands developed an entire series of gerbera with characteristics that provide strong garden performance. The Garvinea series is cold hardy to USDA Hardiness Zone 7 and provides strong resistance against pests and diseases. In the landscape, the plants grow to 18 inches across and 18 inches tall while they are blooming.

One of this series’ greatest attributes is it provides an extended bloom time, producing colorful 2-inch flowers from early spring until the first frost. It is not uncommon for a single plant to produce more than 100 flowers during the growing season. Currently, there are 24 different cultivars, including several with brightly colored flowers, soft-toned bloom colorations, and varieties that have flower heads that change color as they develop.

These robust plants are well suited for container plantings, perennial borders, or for cut flowers. With its strong garden performance the Garvinea series has won several notable awards in Europe, including the HortiFair Innovation Award 2009 and the Golden Floral Award 2010. This innovative and unique selection of garden plants has great potential in the United States. With their extended bloom times, proven garden performance, and wide selection of bloom colorations, the Garvinea series would make an excellent addition to many perennial programs.

Propagation

Gerbera Garvinea cultivars are vegetatively propagated by means of tissue culture. Tissue culture allows them to be grown with great uniformity. Propagation of this cultivar is prohibited. The uniform plant material is multiplied through tissue culture and offered through rooting stations as hardened young plant material in trays.

Production

Liners of Garvinea perennial gerbera are best produced in 5- to 7-inch containers. Growers should use a growing mix that provides both good water holding ability and adequate drainage. Plant them in the center of the pot with the top of the liner being even with the soil line of the final container. Avoid planting liners too deeply; growing mix covering the crown often inhibits proper growth and makes the crop flower unevenly.

Gerbera are light to moderate feeders. Watch the pH closely; maintain levels between 5.5 to 6.0. When the pH rises to 6.5, they may show signs (chlorosis) of iron and manganese deficiencies. These symptoms can be avoided by maintaining appropriate pH levels. Growers most commonly deliver nutrients using water soluble fertilizers containing micronutrients. Maintain EC levels of 1.0 to 1.5. Irrigating them with 100- to 150-ppm nitrogen with every irrigation is usually sufficient. To prevent the salt levels from accumulating, it is recommended to irrigate without fertilizers every third or fourth watering.

They require an average amount of irrigation. When irrigation is required, water them thoroughly and allow the growing mix to dry slightly between waterings. Overwatering gerbera may lead to damaged roots and increases the likelihood of crown and root rot pathogens. If drip irrigation or subirrigation are options, these methods of watering are preferred as they reduce free moisture from resting in the center of the plant which decreases the conditions favorable for plant pathogens.

Since its introduction, Garvinea has been extensively cultivated and tested around the world. Due to its vigorous, all-weather and disease-resistant basis, the series offers advantages for growers. Garvinea can be produced at relatively low temperatures, with little to no pesticides and no growth regulators, matching today’s criteria in which environment and energy saving are key factors. Although, they can generally be grown without cultural issues, it is recommended to routinely monitor the crops to detect the presence of insects (namely thrips and whiteflies) and plant pathogens early and implement control strategies if necessary.

Temperature and Scheduling

The main factors influencing the proper timing of gerbera Garvinea cultivars are temperature and light intensity. Growers most commonly receive liners that are six to seven weeks old. The first three weeks after planting is a hardening and establishment phase; many growers produce them at pot-to-pot spacing during this phase. Grow the plants at slightly lower light levels (2,800 to 4,600 foot-candles) and with temperatures from 59 to 68° F. Provide shading when the light levels exceeds 4,600 foot-candles.

After three weeks of production, space the plants and increase the light levels to above 5,500 foot-candles.

A good final spacing for 6-inch containers is approximately one plant per square foot of production space.

Once the plants are spaced, decrease the production temperatures to 50 to 59° F. Cool temperatures, particularly at night, are important for developing flower buds. Avoid high night temperatures and exposure to temperatures below 41° F throughout the cooling phase.

After approximately three weeks of cooling (nine weeks after potting), flower buds will begin to appear. The Garvinea series reaches a marketable stage 10 to 12 weeks after potting when they are grown as described above. Once the plants are flowering, they will perform well with warmer temperatures; maximum of 95° F.

Growing them cool not only saves energy and promotes good bud set, but improves plant quality by reducing leaf expansion and the height of the flower stems. Some cultivars may show a slight amount of purplish tinged leaves when they are grown cool; this is normal and provides a different look for gerbera and will lessen with warmer temperatures.

Availability

Gerbera Garvinea series is brought to the market by Florist Holland BV (www.floristholland.nl/). Liners are available from numerous rooting stations including Gro’n Sell, Green Circle Growers, Knox Nursery Inc., Pacific Plug and Liner, Plug Connection, Raker & Sons Inc. and Wagner Greenhouses.