You may have heard of the Plant Select® program—a collaboration between Denver Botanic Gardens, Colorado State University and green industry partners. Its mission is simple: to introduce plants that are not only beautiful, but also tough, water-wise and perfectly suited for gardens in the Intermountain West.</p> Behind the Scenes: How Denver Botanic Gardens Shapes Plant Select®</strong></span> </span></h3> At the Gardens, we play a big role in this work. We trial new plants onsite (see an excellent overview of the process here</a>), manage demonstration gardens at both York Street and Chatfield Farms, and offer Plant Select plants at our annual Spring Plant Sale.</p> But here’s something you may not know: the Gardens also helps discover and develop new plants for the program. With over 17,000 plant varieties in our living collections, we have an unmatched resource to draw from. In fact, more than 70% of Plant Select introductions begin here at Denver Botanic Gardens with our staff.</p> Better Plants for the Intermountain West</h3> In recent years, our horticulture research team has launched a focused plant breeding program to create cultivars and unique varieties tailored for our region. Sometimes this means selecting naturally occurring traits from wild populations; other times it involves advanced tools that allow us to shape plant genetics more precisely.</p> Plant breeding is hardly new—it dates back nearly 10,000 years, when early farmers began selecting plants for better yield, flavor, or appearance. At its simplest, it’s just crossing two compatible plants to combine desirable traits. Over the last century, techniques such as mutagenesis and ploidy manipulation expanded what breeders could achieve, and today, gene editing and transgenics allow us to target traits with unprecedented accuracy.</p> At the Gardens, most of our work still relies on traditional breeding methods. That means crossing plants with traits we want to combine—say, the flower color of one species with the drought tolerance of another. By pairing a highly ornamental plant with a drought-hardy relative, we hope to create varieties that are both beautiful and better adapted to hot, dry conditions. It’s a long process, often requiring multiple generations before the right combination is achieved.</p> We also use mutagens, substances that can trigger changes in a plant’s genome. While these changes are random, they often produce predictable outcomes, such as compact growth, novel foliage color, or reduced fertility. We use this technique with plants that already have strong ornamental appeal and environmental tolerance but may benefit from a unique twist or refinement.</p> Beyond Beauty: Our Breeding Goals</h3> Unlike ornamental horticulture at large, our breeding priorities go beyond aesthetics. We aim to develop plants that are not only striking in the garden, but also resilient in our increasingly harsh climate and supportive of pollinators and ecological health.</p> In other words, we’re not just breeding plants to survive here—we’re breeding them to thrive. </p>
Scattering a few ounces of seed onto dry Colorado soil can feel more like hoping than planting. Folks who’ve tried store-bought wildflower mixes might know the frustration: despite following instructions, results are often inconsistent. Mixes may bloom for a season or two but can be patchy, lack coherent design, are soon overrun by weeds, or collapse into stands dominated by one or two aggressive species.</p> Still, direct seeding remains one of the most appealing ways to transform non-functional turf, medians and other tough spaces. Seeds are inexpensive, species are easy to source compared to potted plants, and installation is simple. Our horticulture research team at the Gardens has been investigating ways to make direct seeding more reliable, creating mixes that are beautiful, resilient and long-lasting.</p> Setting Parameters</h3> One challenge with many commercial mixes is the lack of crucial details. Sowing rates are often given in pounds per acre, which is nearly impossible to scale to a backyard or small urban lot. Even worse, weight is misleading: a gram of lupine seed equals about 30 seeds, while a gram of Artemisia can be nearly 10,000. To improve accuracy, we calculate sowing rates based on the number of seeds per unit area (i.e., 300 seeds per square foot). This method allows us to balance species more precisely and adjust mixes to specific sites.</p> Another problem is growth form diversity. Most mixes emphasize only wildflowers, overlooking grasses and shrubs—two of the most resilient growth forms in Colorado ecosystems. However, the right ratio of these various growth forms is crucial. Too many aggressive grasses or shrubs, and diversity disappears. But when balanced, each growth form contributes to a stable and enduring plant community.</p> Choosing the Right Species</h3> Species selection is just as critical. Every plant has unique traits: germination timing, bloom period, lifespan, stress tolerance and competitiveness – among many others. Many mixes rely heavily on species that sprout quickly, which may look good at first but fail to sustain long-term diversity or season-long blooms.</p> Our approach uses trait-based design. We include fast-germinating species that suppress weeds in the first year while leaving room for longer-lived species to establish. We also screen new species for how they perform over multiple seasons, tracking which ones persist, coexist well with others, and extend bloom time from spring through fall.</p> Timing Matters</h3> We’ve also studied how sowing season affects establishment. Standard advice is to sow in autumn so cold weather can break seed dormancy. But our trials show that spring sowing—using seeds pre-treated with cold in refrigeration—often yields higher germination, especially when paired with supplemental irrigation in the first year. Losses from winter die-off, predation, and moisture stress may explain why fall seeding performs less reliably.</p> Built to Last</h3> Direct seeding may never be as predictable as planting nursery-grown perennials. But with thoughtful design, it can be just as successful. By refining sowing rates, balancing growth forms, carefully selecting species, and timing sowing strategically, we’re creating custom mixes that are diverse, resilient and built to last in Colorado’s challenging conditions.</p> </p>
When I talk about my work as a scientist in the Research and Conservation Department at Denver Botanic Gardens, I explain how I study the role of genetic diversity in conserving biodiversity. People often ask for examples of this or cite famous stories of disease resistance, genetic rescue or environmental adaptation. Indeed, there are great examples, such as how a lack of genetic diversity led to widespread disease and die-off of potato crops resulting in the 1800s Irish Potato Famine, or the successful recovery of the endangered Florida panther after introduction of new genetic variation from Texas panthers. I want to highlight a few real-world examples that are specific to plant biodiversity conservation. </p> First, adaptation to new environments is facilitated by genetic diversity. Examples of this include colonization of toxic mine tailings by certain grass species (e.g. Anthoxanthum odoratum</em>), adaptation of yarrow (e.g. Achillea borealis</em>) and other species to serpentine (low nutrient, high heavy metal) soils, and existence of new species or varieties of wild sunflowers (e.g. Helianthus petiolaris</em>) in sand dune habitats. These studies of natural phenomena are particularly valuable to understand in the context of conserving biodiversity under ongoing threats of environmental change. </p> Second, genetic diversity can increase ecosystem function. While the mechanisms for this are still debated, there is ample evidence that complementarity, or differential strategies by different species or genetic variants, allows for improved functioning of ecosystems. In grasslands for example, it has been shown that species that utilize above- versus below-ground space in complementary ways results in higher productivity overall. Or in the case of threats such as herbivores and climate extremes, different plant species can protect or facilitate each other via mechanisms such as nurse plant effects. Together, these examples emphasize the role of genetic diversity in plant communities and the importance of conserving it. </p>
In 2018, Denver residents voted to pass the citywide green roof ordinance, sparking excitement about a greener, cooler, livelier cityscape. Many rooftops transformed into gardens, farms, and pollinator havens. But despite their benefits, green roofs are notoriously difficult to establish—especially in Denver’s semi-arid climate.</p> On a rooftop, plants endure full-sun exposure, with substrate temperatures soaring above 90 degrees in summer and plunging below freezing in winter. The shallow, fast-draining engineered soil holds little organic matter. As a result, designers often rely on sod seeded with Sedum species.</p> While sedum roofs offer benefits, they lack the biodiversity, dramatic colors, and rich textures one might see while visiting Denver Botanic Gardens or hiking the mountain trails of Crested Butte in summer. Colorado’s native species are well adapted to such harsh conditions, yet their potential on green roofs remains largely untapped. Recognizing this, Colorado State University graduate student Maria Schonewise partnered with the Gardens’ horticulture research team to develop native seed mixes capable of establishing naturalistic, resilient plant communities on rooftops.</p> Working with Manager of Horticulture Research Michael Guidi, Schonewise designed a mix of 34 wildflowers, grasses and shrubs, varying seed densities to test establishment. Once developed, her mix was then sown into approximately 60 plots across three Denver green roofs: CSU Spur, Community College of Denver and in the Green Roof garden</a> atop Offshoots Café at the Gardens.</p> Throughout the summer, Schonewise tended plots and collected data on species presence, abundance and weed coverage. These findings will help answer pressing questions: Which plants are tough enough to thrive? How can we create biodiverse, low-maintenance communities? What pollinators use rooftop habitats, and what resources do rooftop native plant communities provide urban pollinators? </p> Her research could help improve upon the industry standard sedum mats used in green roofs by creating a reliable, hardy and biodiverse method for establishing plant communities, making them just as colorful and rich as Colorado’s various landscapes. Next time you visit the Gardens, stop by the Green Roof garden above Offshoots Café to see this living laboratory in action.</p> This article was contributed by Horticulture Research Associate Reece Bailey</strong>.</em> </p>
Our research scientists collect a lot of data every summer—and this work can be challenging. From our work in the field, we’ve learned to come prepared to clear one road that is invariably blocked by downed trees. Then there are the hours we spend on our hands and knees keenly searching for and measuring hundreds of individual rare plants. In small plots at study sites throughout each species’ range, we mark every individual and track their fate year after year. </p> This annual data allows us to correlate climate variables to survival and reproduction. We can then estimate the population’s risk of extinction. In addition to the annual demographic monitoring, we are developing methods to efficiently and effectively estimate the total population size</a> of rare plants. Population counts help us estimate the level of genetic diversity within a population. A sufficiently large population can potentially adapt to climate, habitat and plant community changes. Our data serves to address global challenges. An estimated one million species face extinction worldwide. There is a need to prioritize species and put resources to those most at risk. Tools like the U.S. Endangered Species Act</a> and the International Union for Conservation of Nature Red List</a> rely on population counts and predictions of risk. </p> While we annually collect data all over Colorado on six rare species, all of these help improve and promote effective data collection methods. We are chipping away at the biodiversity crisis by collaborating and sharing expertise with federal and private conservation partners. Our efforts are extended through our participation in the Global Strategy for Plant Conservation</a>. </p> The task may be daunting, but I look forward to clearing the way to collect meaningful and impactful data for years to come. </p>
With leaves falling outside, temperatures getting lower and Halloween creeping closer, it’s the perfect time to curl up inside with a good mystery, thriller or horror novel. If the book is plant-related, that’s even better!</p> The Helen Fowler Library</a> has a great selection of fiction works, and we invite you to browse our offerings this spooky season. </p> Mystery</h3> Mystery books make up a good portion of our fiction collection, including puzzling and atmospheric works like:</p> “Thyme of Death” by Susan Wittig Albert. The first entry in the China Bayles series introduces the mystery-solving herb shop owner who stars in 29 books to date.</li> “Garden of Shadows” by local author Amy Marie Turner. Set in 19th century Spain, botanist Linnea Wren must navigate political intrigue, romance and more while solving a murder. </li> </ul> Thriller</h3> Thriller books in our collection include:</p> “Goldilocks” by Laura Lam. A science fiction thriller set in space with the survival of humanity on the line. The Goldilocks Zone is supposed to be just right for human life but getting there won’t be easy.</li> “The Slime Mold Murders” by Ellen King Rice. A unique ecological pandemic thriller set at Halloween time where the lead character’s expertise on Myxogastria slime molds proves crucial in saving lives.</li> </ul> Horror</h3> Horror works we have lean toward cosmic and ecological horror, which can be really terrifying. Check out these selections:</p> “Parable of the Sower” by Octavia Butler. A dystopian novel with ecological horror elements written in 1993 and set in the then-distant future year of 2024. We have the graphic novel adaptation on hand, and its dark illustrations match the original novel’s tones of horror and societal decay perfectly.</li> “Annihilation” by Jeff VanderMeer. This first entry in the Southern Reach series introduces us to Area X and the cosmic horror lurking within. Winner of both the Nebula and Shirley Jackson Awards.</li> </ul> Nonfiction</h3> Finally, for a great nonfiction book that traces the use of plants and gardening in mystery novels, take a look at “Gardening Can Be Murder.” Expert gardener, historian and author Marta McDowell informs the reader on a plant-by-plant basis of which flora have been implicated in murder in which authors’ novels.</p> For more recommendations, come visit us at the Helen Fowler Library! </p>
Do you have a family recipe that connects you to your roots? Maybe it’s a recipe that each time you smell it sizzling in the pan, you’re transported to your grandmother’s kitchen. Or maybe it’s a recipe you’ve taught to younger generations so they can continue the tradition. </p> For my family, that recipe is krautburgers. These delicious, hand-held pocket sandwiches are stuffed with sauerkraut and beef, and they arrived in Colorado with a small group of immigrants who came to the United States from Russia but were originally from Germany. Each winter, my dad uses an old family recipe to whip up a huge batch of krautburgers. Eating one feels like tapping into the generations of love and wisdom that made me, me. </p> You can explore the deep personal significance of foods and family recipes in Nourished: Works by Jazz Holmes</a>, opening in the Freyer – Newman Center on Saturday, September 27. Artist Jazz Holmes connects to her Creole background through paintings that celebrate traditional Southern recipes like hoppin’ john, étouffée, bananas foster and more. Discover the surprising history behind staple ingredients and the stories of love and labor that go into making and preserving cherished family recipes. </p> Feeling hungry after seeing art about delicious food? Scan QR codes in gallery to access recipes by Jazz Holmes or stop by the interactive recipe-share station to leave a copy of your favorite family recipe for others to try. No matter where your family is from, food has the power to nourish and connect, so share the love! </p> Article contributed by Curatorial Coordinator Katie Foster. </strong></em></p>
Botanic gardens can change the world. Our former CEO Brian Vogt used to say this regularly as he spoke with people about the power of Gardens. There is no better time for botanic gardens to confirm his point than now. </p> As cultural institutions deeply connected with our communities and the natural world, we sit in a place where we can do both the hard work of understanding shifts in our biological landscapes and educate our audiences about these changes and their repercussions. The Gardens’ scientists engage in projects tracking plant and fungal diversity, collecting seeds, producing seeds, understanding genetic influence on restoration success, assessing tree health and long-term population trends. </p> Collaboration is an essential component of our success. As federal policy, regulations and funding availability are shifting, our work is impacted. Now, more than ever, working with others will be required to restore burned and degraded landscapes, conserve species and track shifting species dynamics as invasive species and warmer temperatures change habitats. We need to find new and creative ways to carry our work forward. Leadership around plant conservation is needed now, and Denver Botanic Gardens has a seat at the table.</p> To do this work we partner broadly with public and private entities. Federal policies and regulations shape experimental design and drive our data collection. We aim to understand plant population dynamics and the factors that influence rarity in many of our plants protected under the U.S. Fish and Wildlife Service Endangered Species Act. </p> Based in the heart of the Rocky Mountains, we are leading the North American Botanic Garden Strategy for Alpine Plant Conservation in partnership with Betty Ford Alpine Gardens. Through federal funding we are building an alpine plant atlas to track the location and conservation status of North American alpine plants and are collecting seed of rare species for safeguarding against a warming climate. As federal policies, regulations, and funding have been changing dramatically this year, it creates uncertainty in our work on these projects. </p> In mid-August, I had the opportunity to attend the Plant Conservation Leadership Summit</a>, an event hosted at Atlanta Botanical Gardens and organized collaboratively by the Center for Plant Conservation</a>, the American Public Garden Association</a>, Botanic Gardens Conservation International – U.S.</a> and Atlanta Botanical Gardens</a>. More than 50 conservation and garden leaders from across the country attended in person with another 50 online. The two-day summit presented opportunities to brainstorm, strategize and learn together. We shared approaches for unconventional funding opportunities, policy needs and how to make a good pitch. We talked about the value of storytelling and how we need to do more to put plants back in the national mindset. </p> Three Denver Botanic Gardens’ staff attended, and we all walked away energized and committed to not only enhancing the role that the Gardens plays in our local conservation landscape, but on a national and international stage as well. Many opportunities are on the horizon, and we are ready to use our expertise to lead. Despite the uncertainty that has hit our field and our funding this year, I am inspired and hopeful about our future and the opportunities to conserve plants. </p> So, in alignment with what Brian would say, botanic gardens are poised to save the world—or at least make a really good effort to protect it together. </p>
