You may have noticed that I’ve been focusing on native plants a lot lately. They have so much to offer in the garden – both to you, as the gardener, and to the wildlife in your area. I’ve been an advocate for native plants for many years, but a recent trip lit a new fire in my passion for these underrated species.
Earlier this year, the crew and I spent time at Mt. Cuba Center to film an episode of my PBS show, Growing a Greener World®. I’ve long been a fan of native plants, but time spent at Mt. Cuba really knocked my socks off. So for this podcast, I asked George Coombs, Manager of Horticultural Research, to join me for his take on native plants and to share more on the history of this organization and the scope of its work.
Mt. Cuba Center
Located just outside of Wilmington, Delaware – about 40 miles southwest of Philadelphia – Mt. Cuba Center was once the private gardens of Lammot Copeland and his wife Pamela. Lammot was heir to the DuPonts, one of the wealthiest families in America in the early 20th Century. Pamela had a deep appreciation for native plants and was decades ahead of her time in recognizing their ecological value and the need for their conservation in the wild.
Together, the Copelands developed their vast estate gardens using primarily just the plants native to their area.
By the 1960’s, other gardeners were beginning to appreciate the beauty of “wildflowers” too. However, these plants weren’t available for purchase, so gardeners were digging them up from area forests and meadows. Mrs. Copeland was concerned about the destructive effect of wild harvesting and implemented work to propagate the native plants on her estate to make them available for sale at local nurseries.
As time passed and the estate gardens grew to 1,100 lush acres with thousands of native varietals. Mrs. Copeland chose to donate the estate. It was her wish that the property would be maintained with a mission of instilling in others an appreciation of nature and native plants, in particular. Today, Mt. Cuba Center honors that mission and is the premiere public garden for viewing native plants in their full, dazzling glory.
If you think native plants are lackluster, you haven’t been to Mt. Cuba Center.
There’s much more to Mt. Cuba Center than just beautiful grounds. The staff aims to inspire gardeners to incorporate natives in their own landscapes and offers classes to the public – for gardeners of all levels – on conservation, pruning, pollinators & other wildlife, health & wellness, art, and many other educational sessions. There’s also an intern program for training the next generation of horticulturalists.
Another important objective of Mt. Cuba Center is native plant research. A world-renowned resource for industry experts and weekend warriors alike, their website will wow you with gorgeous photography and rich information.
During my time at Mt. Cuba Center, I had the opportunity to tour their Trial Gardens and watch George at work. George calls the Trial Gardens the Consumer Reports for plants. Each trial focuses on different varieties of one species.
Plant species are grown together in the same area and under the same conditions for, typically, three years. During that time, George and staff are collecting all kinds of data. Measuring growth; observing pollinator response, drought tolerance, pest and disease resistance; and identifying which varieties perform best overall.
Trials are meant to be a real world “stress test” – so after helping plants to get established, the staff takes a very hands-off approach. Actually, George says his job is to be the worst gardener at Mt. Cuba. Trial plants receive little care or supplemental watering. The whole point is to see which varieties stand out among the pack under natural conditions.
Mt. Cuba Center strives to arm gardeners with information on which native plants will thrive in the landscape without any coddling. All of their research and recommendations are provided on Mt. Cuba’s website, so you can see for yourself which native varieties will be a good fit for you.
Beyond the Beauty
Have you ever considered that plants are the foundation of every ecosystem? As George points out, they are the only living things which can create their own energy. Everything else up the food chain – all the insects, birds and larger creatures – relies on plants.
In many instances, plants native to an area are the only thing native insects and other creatures can feed on. Plants which have been imported or specifically bred for their aesthetic characteristics often don’t provide what native wildlife need.
Mt. Cuba Center is just as interested in the ecological value of plants as they are in making sure a plant performs well. Mt. Cuba has partnered with graduate students of the University of Delaware horticulture program and with volunteers for a “pollinator watch.” Volunteers observe plants, like various phlox varieties, to count – literally count – the number of pollinator visits to each variety of plant. The intent of the study is to try to identify which plants attract (and, therefore, support) more pollinators and which plant characteristics drive the preference.
Recently, they found that Phlox paniculata ‘jeana’ was highly favored by all sorts of butterflies, particularly swallowtails. Of the many phlox varieties, all being grown in the same area, butterflies were noticeably most drawn to the jeana variety. Why? The results aren’t in yet, but the graduate students have hypothesized that it’s because jeana’s flowers are much smaller and closer together than other phlox varieties. This means the nectar is closer to the surface of the flower, and the butterflies can move more quickly from bloom to bloom.
You don’t need to be a graduate student or a horticulturist to observe wildlife at work in your own landscape. Spend a little time to see what’s going on out there, and you will learn which plants your area pollinators or birds consider “the good stuff.”
A Little Science
Phlox paniculata ‘jeana’ is a cultivar of the phlox species. Cultivars are the result of someone observing something about a particular plant which makes it different than the others in its species.
The different plant is then cultivated to create genetically-identical new plants to preserve its unique characteristics, and it’s named to provide a unique identifier. Cultivation is done asexually through propagation – taking a part of the plant, like a section of stem and leaves and encouraging that part to take root. This creates a clone of the original plant.
While the cultivar may offer some desirable traits, there is no way to know how the genetic anomalies, which created the new traits, may have also altered something important to the insects or wildlife that depend on the original variety.
George gives the example of the tomato. Most consumers prefer tomatoes which are a full red color. So, tomato varieties which grow totally red tomatoes have been cultivated for commercial production. Recently, it’s been discovered that the genes which create the rich tomato flavor we all love are tied to the genes which hold some green coloring at the top of the tomato fruit. By cultivating the all red tomato, we get the desired color, but genetically, we lose flavor into the bargain.
Have you heard the term “nativar”? A nativar is just a cultivar of a native plant. Nativar was a moniker coined to indicate to consumers that a plant is a native variety.
So, what about hybrids? A hybrid plant is a cross between two plant species. Since the genetics of two plants come together in a hybrid, the resulting plant’s characteristics are altered much more drastically than a cultivar. For that reason, hybrids are less likely than a cultivar or nativar to provide ecological benefit. There’s a greater chance that the genetic alteration created a loss of a trait important to wildlife.
Double-blooming flowers are a great example of a hybrid with little ecological benefit. Sure, that mass of petals is beautiful to look at, but double blooms provide less – and sometimes no – pollen or nectar.
Minimal Work – Maximum Impact
One of my visits to Mt. Cuba Center was in May of this year. I was overwhelmed at how much was in bloom. Everything in view was a native variety, and everything was truly breathtaking. I know I’m repeating myself here, but a stroll around Mt. Cuba Center will convince you that native plants aren’t messy or weedy. They provide showstopping bloom, foliage and structure.
That said, George points out that native plants aren’t just beautiful in spring – they offer multi-seasonal interest. Because these plants evolved together, there is a natural rhythm to their progressive displays all throughout the season, without much – if any – input from the gardener.
Still not sold on natives? Consider this: Having visited many public gardens throughout my career, I can attest to the fact that most are changing out their displays each season to create interest for visitors. At Mt. Cuba Center, they allow the plants to do this on their own – minimal effort but, let me tell you, maximum visual impact. A garden of native plants isn’t one that cares for itself, but it is a garden that is fun – and easy – to care for.
The bulk of Mt. Cuba’s garden work revolves around editing the landscape and varying plant layers. Native plants will multiply, so plants need to be removed to prevent the space from becoming too crowded. Dense planting is a good way to suppress weeds naturally. However when things get too dense, air and light movement are restricted, which contributes to issues even with native varieties.
As plants are removed from the Mt. Cuba Center landscape, they are relocated to other areas or, often, given away to volunteers and visitors. Hint hint.
Choosing for Your Garden
My hope – and the hope of everyone at Mt. Cuba Center – is to arm you with the best information; so you can make better, smarter choices in your garden. Don’t feel that, if you have exotic and hybrid plants in your landscape, that you’ve failed and need to start over. If you choose to replace everything with native plants, you will certainly be going above and beyond to support local wildlife. But it isn’t necessary to take such drastic steps.
Just add some native plants to your garden – Mt. Cuba Center calls it gardening by addition. Or, replace a few of those purely aesthetic plants. Either way, you will be making a valuable difference.
As you purchase plants, consider the functional and ecological value – rather than just the aesthetic. Once you do just a little research, you will find that function and beauty don’t need to be mutually exclusive. There is a whole world of color and form in native species that most gardeners don’t realize. Why? Only because there isn’t a readily-available variety at most local nurseries, garden centers or box stores.
This is a chicken-and-egg problem. Native plants aren’t seen as sale-able, because consumers don’t buy as many natives. Consumers don’t buy as many natives, because there isn’t enough variety available to convey the full scope of aesthetic beauty that natives can provide as well – or better – than the exotic plants which have become so ubiquitous.
Recently, Mt. Cuba Center completed a survey of the Mid-Atlantic nursery industry and found that only about one quarter of plant inventory is made up of natives. So, Mt. Cuba is actively working with growers and plant producers to provide the industry information on which natives are the best candidates for commercialization. Their aim is to get more native plants into mass distribution.
Imagine the far-reaching benefits of having more native than exotic plants available for all gardeners to purchase.
As consumers, we do our part by talking to the staff of nurseries and garden centers. Create demand. Let them know you will support their efforts to stock more native plants.
There are many online resources available (including the Mt. Cuba website) where you can educate yourself on the diversity of plants native to your region. Your local county extension office can provide information too. Once you find varieties you like, ask the nursery for them. They may be able to order those plants for you.
Native plants aren’t a mainstream “product” yet, but we are moving in that direction. As long as we keep asking for more, and through Mt. Cuba Center’s efforts to provide more and better information to growers, we can continue to increase demand – and, then, supply.
Home Gardeners in Action
Hopefully by now, you’re eager to add some native plants to your garden beds. If it isn’t a good time to plant where you live, you can still take some immediate steps this fall to provide for beneficial insects, birds and other wildlife in your neck of the urban woods. And you’ll be pleasantly surprised to know these suggestions save you money and time.
Do a Little Less Maintenance
Be a lazier gardener and do wildlife a favor – prune less and don’t feel the urge to tidy things up as we’ve traditionally been taught to do. The dried seed heads of late fall are an important food source for birds. Debris, like dead perennial growth, offers shelter to overwintering insects. Postpone clearing these materials out of your garden until late winter or early spring.
If you’ve lost a tree this season, let the stump or a tree snag or two remain in place. They will provide shelter for wildlife, which will bring more balance to your little ecology.
Use Leaves as Mulch
Instead of buying mulch, use one of the best gifts nature gives us each year – fallen leaves. They are free and one of the best materials you can use to mulch. They’ll protect garden beds over winter and break down to provide important nutrients for richer soil year after year.
Reduce Your Lawn Space
Lawns are ecological dead zones. This doesn’t mean you need to remove all of your lawn. In fact, I’ve incorporated lawn space into my five acre GardenFarm. The point is to strive for more balance. Create more habitat by incorporate native plant beds and adding a few more trees.
Did you know that white oak trees are one of the most ecologically valuable native trees of North America? They support over 400 types of caterpillars – which are a vital food source for birds.
Don’t feel pressured to fill your landscape with plants all at once. Add plants over time and observe how local wildlife interacts with them and how they perform in your space. Let those observations be your guide as you incorporate more – and, remember, those native plants will generate more free plants you can tuck into new spaces.
Share Your Observations
By sharing observations – and maybe even some of those extra native offshoot plants – with other gardeners in your area. This is how we all learn – together – how to continue to improve our collective environment.
What have you observed about the plants in your garden? Are there varieties that seem to be more popular with pollinators? Share what you’ve seen (along with your hardiness zone) in the Comments section below. You may be providing some helpful tips for others who garden in a similar climate.
I hope you’ll listen in to my conversation with George (if you haven’t already) by clicking the Play icon in the green bar under the title at the top of this page. We had a great discussion, and I think George’s humor and passion for his craft will inspire you. Then, watch the episode we recently aired featuring Mt. Cuba Center, so you can view a tour of this remarkable place and see some of the beauty of these native plants for yourself.