Mt Cuba Center
Mt Cuba Center
Back to News In The News – June 26, 2018

In The News

Native Plants by the Numbers

Mt. Cuba Center researchers evaluate biodiversity in regional plant nurseries

Hockessin, Del. (May 30, 2018) – After a late and rainy spring, it’s finally safe to stroll the aisles of the garden center and take time to—quite literally—stop and smell the roses. The plants that bloom on the garden center bench eventually make their way to our yards and landscapes.

Much like a grocery store with farmers and suppliers who fill the produce section, the garden center is the part of the supply chain that is closest to the average consumer. Behind it are a lot of people who work to bring plants to the gardening public, including the botanists who develop the plant selections, and the wholesale nurseries which grow them to supply to garden centers. All of this provides the palette of possibility we see when we shop at the garden center, but what appears to be a wide variety is just a small slice of what can grow in our region.

In a recently published study, researchers at Mt. Cuba Center have studied the offerings at wholesale plant nurseries—which supply garden centers and landscape companies—to examine the diversity of what’s on sale. Garden centers do their best to offer high-quality plants that will catch the eye of gardeners, but before this study, not much was known about the overall diversity of plants they sell, or the number of available plants native to our region.

“This research forms a baseline for us to measure future trends in plant sales,” said George Coombs, Mt. Cuba Center’s horticultural research manager. “We didn’t really have any idea as to which plants are being grown here, so we needed to study this.”

Mt. Cuba Center’s researchers found that there are close to 7,000 different types of plants grown at wholesale nurseries in our region, and while most of those plants in the trade are non-native ornamentals like hostas and roses, 25% are plants native to the eastern United States that benefit local ecology, like alumroot (Heuchera sp.) and coneflower (Echinacea sp.). Worryingly, 2% of plants available are considered invasive in Delaware, meaning they threaten biodiversity. These are plants like winged euonymus (Euonymus alatus) and Bradford pear (Pyrus calleryana).


The retail ecosystem for garden plants can be boiled down to a simple supply chain. Wholesale nurseries grow plants, which the garden centers purchase. Then, garden centers promote and sell the plants to the gardening public. The gardening public purchases these plants to put in their gardens.

“There’s a lot of diversity that could be out in the industry,” Coombs said. “When you look at the gardens at Mt. Cuba and all the species we have here, most of them are simply not represented in the trade, even if they would be a really good garden plant.”

Shoppers are drawn to plants that are flowering, so garden centers tend to stock plants that are in bloom, or about to bloom, and plants that aren’t picture-perfect can get left behind. For example, Baptisia, or false indigo, is a native perennial that is long-lived, provides beautiful flowers in a variety of colors, benefits bee populations, and is deer-resistant. However, in the garden center it can look like just a few stems in a pot.


Last year, Mt. Cuba Center’s researchers surveyed the available plant lists from 14 medium- to large-scale mid-Atlantic nurseries that provide a robust snapshot of all the types of plants sold in the region.

What the research showed greatly interested Coombs who, when not researching what’s on sale at local wholesale nurseries, runs Mt. Cuba’s Trial Garden where he tests different selections of native plants to find out which thrive best in our region’s climate and conditions.

“This research is going to help us develop priorities for our trials,” Coombs said. “If there’s a plant that we think is beautiful, but is not abundant in the trade, we could help by providing more information about that plant, or researching how to better propagate it. It gives us perspective on what’s really happening in the industry so that we can step back and check the tools in our toolbox.”

The goal, overall, is to increase the number and variety of native plants available in the industry.

“We were surprised. There’s a broader diversity of natives at the wholesale level than we anticipated. I think there are probably some native plants garden centers could easily add to their standard purchasing order that are already out there and will do well in the home garden.”


Local garden centers are frequently the best place for purchasing plants because of their knowledgeable staff members who can advise customers on how to grow and care for them once they are in the ground.

“When you ask for something and they don’t have it, they might realize they missed an opportunity to sell a plant,” Coombs said. “And they’ll say maybe they can get it into the store next week, or next season.”

By asking for native plants by name, each consumer can influence the diversity of plants on offer at the garden center. Communication and feedback flows between each link in the supply chain, and a customer request can help alert suppliers to the increased demand for native plants.

This article originally appeared in the News Journal on June 5, 2018. Read it here.