April 2024 Culture
Culture Report: Cultivating the beauty of Viola ‘Silver Gem’ By Arden Pontasch

After 20 years, this wild variant is now an excellent pick for your perennial program

At North Creek Nurseries, a wholesale propagation nursery in southeastern Pennsylvania with a strong emphasis on North American native plants, we pride ourselves on growing plants that stand the test of time. That test begins in our trial gardens and expands to every inch of the company, as we constantly assess the resiliency of each plant within our internal greenhouse and production processes, too.

The means by which a plant is introduced to the nursery trade, while often nuanced, is also often a testament to the character of those plantsmen who know when a plant that is worthy of said nuance has graced their gardens. While the path to introduction has been somewhat circuitous for Viola walteri ‘Silver Gem’, the charisma of the striking — almost glowing — silvery foliage and the dainty lavender flowers, which float effortlessly above the stretching tendrils, make this plant a horticultural specialty to add to your perennial product lineup for 2024 and beyond.

‘Silver Gem’ plants propagated by tissue culture are ready to be planted in plug trays.

‘Silver Gem’ was first discovered along a tributary of the Little Cahaba River in Bibb County, Alabama, in 2003 by Rick Lewandowski, then director of Mt. Cuba Center in Hockessin, Delaware, and Fred Spicer from the Chicago Botanic Garden. This wild seedling variant was spotted in the rich woodlands, near an exposed cedar glade on a dolomitic limestone outcropping and stood out with its distinctive silvery foliage amidst the plentiful and typical green-to-grayish leaved forms of Viola walteri in the population. After its discovery, the plant spent seven years at Mt. Cuba Center as it was propagated (asexually) and planted out in the gardens.

A key vision of Mt. Cuba Center — imparted to them in no small way by the late Mrs. Lammot duPont Copeland — is to promote a broader availability of high-quality, improved plants for the greater gardening community by evaluating and introducing plants which can be successfully nursery propagated, while combining robust ornamental appeal and broad regional adaptability.

Tissue cultureplants of ‘Silver Gem’ have been planted in soil and will enter a mist house until rooted. Photos courtesy of North Creek Nurseries. — Tissue culture plants of ‘Silver Gem’ have been planted in soil and will enter a mist house until rooted. Photos courtesy of North Creek Nurseries.

The partnership between Mt. Cuba and North Creek is a friendship that runs deep and spans decades. When the decision to share ‘Silver Gem’ with the nursery industry was made back in 2010, the decision as to who to contact was easy. The following year in 2011, 161 flats were sold at North Creek, immediately engaging industry interest. North Creek was able to produce new plants from our own stock for about seven years. Over time, although industry interest expanded, stock plants had grown weaker and less capable of rooting successfully. By late 2019, a need for change was recognized, and the decision was made to switch production methods from stock plants to tissue culture.

After initiation, the tissue culture lab worked to refine their production methods, and North Creek collaborated with them to navigate the timing and quantities of shipments of inputs. Today, numbers are expanding, and inputs are looking better than ever!

“We are also experimenting with augmented windows of availability,” Courtney Knight, North Creek production administrator, said. “‘Silver Gem’ thrives in cooler conditions, so we began offering it with midwinter potting in mind. However, with more demand and better input availability, we are excited to also offer larger quantities of plants for fall and spring planting windows, as well.”

Please reference our website for current offerings and projected future dates of ‘Silver Gem’, we hope you find joy in the growing and garden-worthy nature of this gem!