Gather ‘round, green-thumb enthusiasts. It’s time to get the dirt on carbon sequestration and unearth how our gardens can be unsung heroes in battling climate change.</p> What is carbon sequestration? As one might remember from biology class, when plants photosynthesize, they absorb carbon dioxide (CO2) from the atmosphere. This is carbon sequestration, one of nature’s ways of cycling nutrients. </p> Human-induced climate change was and is caused by excessive emissions, including CO2. Sequestering carbon mitigates the harmful effects of climate change, and even the humblest garden does it. For gardeners looking to steward the environment and future generations, consider employing techniques that enhance carbon absorption and storage. Gardeners can boost their garden’s carbon sequestering potential by implementing these practices:</p> Cultivate healthy soil.</strong> Healthy soil acts as a major carbon sink. Recovering and protecting soil has the potential to sequester 5.5 billion tons of CO2. Gardeners can protect and replenish soil by leaving perennials up during the winter, mulching, composting and minimizing tillage. These garden practices add organic matter to the soil, creating habitat for carbon-storing microbes.</p> Limit chemicals.</strong> Many fertilizers and pesticides depend on fossil fuels, be it during production, in the ingredient list, or both. These chemicals also end up polluting waterways, which causes a slew of environmental problems. For example, buildup of pollutants causes anaerobic conditions, i.e., "dead zones." With oxygen choked out of the ecosystem, so follows many other organisms. This limits opportunities for carbon-to-oxy exchange and emits even more carbon dioxide. Bonus: scale up. </strong>Climate change data and news often feel hopeless. One of my go-to strategies has been to examine what I have control over and where I can act. This truth also needs to be balanced with the reality that carbon sequestration must happen on larger scales as well. Consider how you can push for collective action through local government, neighborhood groups, nonprofits or other avenues. By actively engaging in practices that sequester carbon, gardeners can contribute positively to the environment while also nurturing their gardens. </p> Let us dirty our hands and watch our gardens champion over climate change. Every little green thing you grow gives back. So, I encourage you to keep planting, nurturing and growing a greener future.</p> This article was contributed by Horticulturist Abigail McLennan.</strong></em> </p>
Calling all Brownie Girl Scouts who are looking to “go green.” On Saturday, February 3, join us at Denver Botanic Gardens for our Household Elf Girl Scout Exploration Day and learn how your scout can make a positive environmental impact. </p> This Exploration Day, designed to meet the requirements of the Household Elf badge, helps Girl Scouts explore the Gardens in a whole new way as they learn how plants conserve water and energy, and how they can help the planet by conserving water and energy, too. Participating Girl Scouts also take a stylish step in reducing waste by decorating their own reusable bag, and—bonus—get their hands dirty planting an air-purifying plant! </p> Learn more about this program</a> and how you can register your Girl Scout or troop.</p> Let’s work together to make the world greener, one step at a time. </p> This article was contributed by Family and Children's Program Coordinator Helena Nitz.</strong></em></p>
Compost seems to be a hot topic these days. We all love the thick white steam cloud emitted from a healthy compost pile in the cool mornings of the fall, but what happens to a compost pile during the winter?</p> Unfortunately, most compost piles freeze solid in the coldest winter months. When a compost pile freezes, however, it isn’t lost forever. As microbes become less active, they no longer produce enough body heat to keep a pile from freezing. Just like us, soil microbes slow down in the cold. But microbes have an ability humans can only mimic in the coldest months of the year: dormancy.</p> A frozen compost pile isn’t dead; it’s dormant. In winter months, soil microbes enter a state of deep hibernation until the conditions are optimal to become active again. In some cases, ancient microbes can remain dormant for thousands of years, waiting to reemerge when a combination of oxygen, moisture and temperature form their ideal microclimate. The vast majority of compost microbes survive even the deepest freezes for a few months.</p> But what if there was a way to keep compost active in the coldest months of the year? While it is possible to keep a compost pile warm in the winter through frequent turning, snowy and icy conditions can prevent farmers and gardeners from accessing their piles. What if there was a way to keep compost warm without turning it?</p> Aerated Static Pile (ASP) composting can keep piles warm through the winter. By “forcing” air through a PVC pipe frame, ASP composting can oxygenate the center of a pile without having to turn it. While traditional compost piles should be covered with a "breathable" material, ASP systems can be sealed with a tarp. Tarps keep moisture in the pile while oxygen is introduced from outside of the pile through the forced aeration. </p> At Denver Botanic Gardens Chatfield Farms</a>, we are installing an ASP composting system this winter. While Chatfield Farms produces around 100 tons of compost a year, ASP systems are relatively easy to build at any scale. A home gardener could build an ASP system with a leaf blower and a few PVC pipes.</p> ASP composting is a great experiment to keep a “soil nerd” occupied through the offseason, but it is by no means the only way to create quality compost. So, whether your compost goes dormant during the winter or stays active year-round with an ASP system, keep up the good work!</p>
As the newly established floristic and outreach coordinator, this year I joined our Research & Conservation Department on various field adventures across Colorado. From the prairie of the Eastern Plains to the canyonlands of the Western Slope, I collected data and asked questions with the intent of better understanding the work of scientists in this department, from their research objectives to methods of collecting data. </p> Early in the season, I joined an expedition studying populations of Colorado hookless cactus, or Sclerocactus glaucus</em>, on the Western Slope. Previously classified as a Federally listed threatened species, our team has been monitoring this species’ population dynamics since 2008. This data contributed to the cactus being de-listed from the Endangered Species Act, ideally freeing up resources to protect other rare species. Although this area near Grand Junction can be dreadfully hot in the summer, in April it was perfect—chilly and overcast. The red of the canyons contrasted strikingly with the green junipers. Although afternoon thunderstorms would threaten our ability to conduct field work, throughout the week we set up transects based on previously monitored plots and collected data on the cactus.</p> In the alpine, we trekked up Hoosier Pass to search for the rare Weber’s saw-wort (Saussurea weberi</em>) for seed collection. The seeds of this and other rare, alpine species are stored in ex-situ collections to help with potential population recovery amid climate change and other threats. We also conduct experiments on the seeds to determine their germination preferences and ability to be stored for long periods of time. Our quest was frequently impeded by breathless pauses and sightings of curious pika, but we found several of the little plants, nonetheless.</p> Moving further east to the plains, we surveyed the Ballyneal Golf Course’s rough areas, aiming to expand the collections in the Kathryn Kalmbach Herbarium</a>. Our natural history collections focus on Colorado, but the Eastern Plains tend to be under-collected, due to private land and agriculture. We roamed through the billowing needle-and-thread grass (Hesperostipa comata</em>) and prairie spiderwort (Tradescantia occidentalis</em>), which sparkled like purple jewels across the verdant prairie. By collecting species with flowers or fruits, we aimed to document the area’s biodiversity. </p> These snapshots offer only a glimpse into our team's remarkable work. From uncovering species new to science to understanding Denver's urban ecology, our endeavors have local and global scientific significance, all while fueling our passion for exploration. </p> This post was contributed by Floristic and Outreach Coordinator Alissa Iverson</strong>.</span></em></p>
It may be years before I fully process my experiences in Tajikistan. The scale of the land, the richness of the flora and the ferocity of our travel schedule still boggles me. As I reminisce, the most extreme impressions are the first to flash across my mind: countless bands of jagged mountain peaks stretching across the horizon like brain coral, idyllic aquamarine rivers loaded with rock flour from ancient glaciers, endless colonies of spined cushion plants coating miles of bone-dry scree.</p> From August 24 to September 6, Associate Director & Curator of Steppe Collections Mike Bone and I traveled through Tajikistan with our colleagues from the Chicago Botanic Garden, Jess Goehler and Lindsey Muscavitch. We were on a seed-collecting expedition to expand the steppe and alpine collections of gardens in the Plant Collecting Collaborative (an alliance between North American gardens supporting important domestic and international collecting trips). Additionally, our goal was to facilitate exchanges of plant material, resources and education between our countries and botanical institutions. In Tajikistan, we primarily worked with Dr. Hikmat Hisoriev of the Institute of Botany, Plant Physiology and Genetics, National Academy of Sciences Tajikistan</a> and Dr. Mario Boboev, director of Kulob Botanic Garden, who acted as our botanic guides and cultural emissaries.</p> Our explorations took us across much of the navigable country, from the northern lake preserve of Iskanderkul in the dramatic Fann Mountains to the eastern city of Murghob deep on the ancient Pamir Highway. Although our focus was primarily on steppe and alpine species, we explored and collected adventitiously along our route, which took us through breathtaking and often treacherous landscapes. Geographically and climatically speaking, Tajikistan is an incredibly diverse country. More than 93 percent of Tajikistan is mountainous, with the highest peaks reaching over 24,000 feet. These topographic extremes create quickly shifting ecoregions ranging from arid desert to polar tundra and subtropics to semi-arid steppes.</p> By the end of our trip, we had made 110 seed collections, representing 97 unique species. Following USDA-APHIS guidelines, we cleaned, inventoried, packaged and shipped our seeds directly to their ports of entry for inspection. This ensured that any pests or pathogens we might have missed during cleaning were detected. While most of the seeds will be grown at the Gardens for inclusion in our steppe and alpine plant collections, some will be cultivated by our Plant Collecting Collaborative partner gardens, and others will be saved in our seed herbarium for further research.</p>
Gardening is a complex endeavor. A symbiosis with countless living things, both seen and unseen, and the management of numerous interactions with the nonliving world. As such, it can be challenging to troubleshoot the underlying causes of poor garden performance or unexpected behavior of plants in the garden. Sometimes, it's best to go back to basics. And soils are often, quite literally, at the root of it all.</p> This year, the horticulture research team implemented a large field experiment at Chatfield Farms to determine the most effective combinations of soil amendments and mulches to improve soil characteristics, reduce water loss, limit weed growth and promote healthy ornamental plant growth. In early spring, we prepared over 16,000 square feet of land at Chatfield Farms. We removed existing vegetation, incorporated amendments into the soil, and applied mulches to the soil surface. Our team monitored plant growth, phenology and weed invasion throughout the season and sampled soils for physical and chemical analysis. Instruments were also installed in each plot to continuously measure the soil temperature and moisture content throughout the study.</p> Despite a dizzying amount of information in magazines and on the web, there is relatively little empirical research on this subject, especially for semi-arid regions like the Front Range of Colorado. The results from this work will help to inform our Sustainable Landscape Services</a> program and our general horticultural practices at the Gardens.</p> An exciting feature of our study is that only native and regionally adapted plants with low water requirements are included. Generally, this group of plants does not require high soil fertility or lots of organic matter. Instead, excellent drainage and open pore space are thought to be more important, which goes against common horticultural wisdom urging gardeners to apply composts and organic mulches to improve soil fertility and texture. We hope the results illuminate best practices for this understudied group of landscape plants.</p> Mulching and soil amendment practices have also been shown to significantly influence how water from precipitation and irrigation infiltrates the soil and how much of that water is lost through evaporation. Through this study, we can compare how unique combinations of amendments and mulches differ in their ability to capture and retain precious water, recommendations that will further our goal of water conservation horticultural practices.</p> If you are interested in hearing about the preliminary results from this work or taking a deeper dive into soil science, members of our horticulture research team will present at the Landscaping with Colorado Native Plants Conference</a> this February. </p>
