PROJECT LEADER(S): Thomas G. Ranney, Thomas A. Eaker, and Joel Mowrey
‘Venus’ is an extremely promising new nursery crop that was developed at NC State with support from the North Carolina Association of Nurserymen, The Golden LEAF Foundation, and the J. Frank Schmidt Family Charitable Foundation. This cultivar is an advanced hybrid that has demonstrated excellent adaptability, pest resistance, stress tolerance and exhibits exceptional ornamental features that transcend what has previously been found in sweetshurbs (Figure 1.). ‘Venus’ represents a considerable breakthrough - there is nothing else even remotely similar in the market.
Although ‘Venus’ looks very promising, we needed to develop and refine propagation protocols, develop specific production practices, and propagate stock plants for distribution to growers and for regional trials. Promotional materials needed to be developed and marketing efforts needed to be initiated.
The objectives of this project were to:
Propagation studies were conducted to optimize and refine production protocols. Summer, sub-terminal cuttings were evaluated for rooting potential following treatment of the basal 1” of the cutting, for 5 sec., with a range of auxin (potassium form of indole-3-butyric acid dissolved in water) concentrations. Production demonstrations were developed for tours and field days. A stock block of ‘Venus’ was established to provide North Carolina growers with a source of propagation material. Plants were propagated and distributed to growers. On-farm trials were established with growers across the State.
Propagation. Propagation studies found that ‘Venus’ can be produced by summer stem cuttings with the use of supplemental auxin treaments. Rooting increased from 50% with no treatment to 100% when treated with KIBA at concentrations of 4,000 to 10,0000 ppm (Fig. 2). Root number increased linearly with increasing auxin treatment and ranged from approximately 6 roots per cutting for no treatment to over 40 roots per cutting when treated with 10,000 ppm KIBA (Fig. 3). Cuttings develop a strong root system and often bloom after rooting (Fig. 4 and 5). Our current recommendations are to propagate ‘Venus’ using 2-node (strip bottom pair of leaves), firm, subterminal cuttings and treat the basal 1” with 8,000 – 10,000 ppm of KIBA dissolved in water, and place cuttings under periodic mist. Cuttings can be stuck in large celled flats or directly into quart pots with a well drained medium.
Demonstrations and Trials. Container and field production demonstrations have been established at the Mountain Horticultural Crops Research Station. These demonstrations were included in tours for nursery growers. Presentations were also made at the Southern Nursery Association Research Conference, North Carolina Green and Grow ’n’ Show, Southern Plant Conference, Eastern Region International Plant Propagators Meeting, NC State Twilight Field Day, NC State Nursery Short Course, Blue Ridge Horticulture Association meeting, and numerous county extension programs including over 1,400 people. Plants are on display at the North Carolina Arboretum, the J.C. Raulston Arboretum, and at numerous county extension offices. On-farm trials have been established with the following growers and most are now producing this plant:
Appalachian Trees, Hollis Wild
Camellia Forest Nursery, David Parks
Carolina Native Nursery, Bill Jones
Clark’s Liner Farm, Debbie Clark
Culture for the Earth, Carol Propest
Fry Nursery, Richard and Pamela Fry
Hawksridge Farms, Inc., Rick Crowder
Highland Creek Nursery, Brian Upchurch
Meadowbrook Nursery, Jamie Oxley
Silverfox Nursery, Kelly McCartney
Tarheel Native Trees, Sam Allen
Old Courthouse Nursery, Sean Gurkin
Stock block. A stock block of 50 ‘Venus’ shrubs has been established at the Mountain Horticultural Crops Research Station. These plants will be available as a source for propagation material for North Carolina nurseries.
Distribution of Stock Plants. Over 500 plants were propagated and distributed for stock plants and for evaluation. In addition to distributions to NC growers, plants have been sent to institutions (Universities, Arboreta, etc.) around the country for promotion and evaluations.
Promotional materials. Images and slides of ‘Venus’ have been distributed and are available upon request. Posters and flyers have been developed and distributed to producers (Fig. 6).
Initial results look very promising. There is considerable excitement about this plant. However, the ultimate success of this plant will depend on its performance in nurseries and landscapes around the world over the next few years.
Updated February, 2005