Less than a year and a half ago, I stumbled into hobby gardening as a distraction from stress. My fascination with the alchemy that is plant science and development grew, and I switched my major from biomedical engineering to horticulture halfway through the summer on an impulse. In my first lecture I heard horticulture described as both a science and an art. At that time, this was an abstract concept to me, though I had an intense desire to learn more about this interaction. </p> Less than a year from that day, I sit writing this having developed both as an artist and scientist through an internship with Bonsai Specialist Larry Jackel in the Bill Hosokawa Bonsai Pavilion. </p> As an intern specializing in Bonsai Collection Management and Curation, I spent a significant portion of my time photographing the entire bonsai collection for our plant records database, in order to monitor changes in the health and styling of the trees over time. Though this was the main project I had to complete, most of my internship was spent learning the methods, techniques and design concepts for bonsai culture in an apprenticeship format. This included the development and understanding of three concepts. </p> The first of these concepts was “to achieve horticultural mastery of plants in pots.” This scientific base allows the art to exist; in the words of my mentor, “A dead tree in a pot is not bonsai.” Horticultural mastery includes frequency and quality of watering, in-depth analysis of the benefits of porous and highly inorganic substrates and soil components, as well as common fertilizing practices. </li> The true fusion of science and art happens through the management of new growth, which was the second concept. This included learning several skills unique to bonsai culture, plus a few universal skills: fine pruning as a method to improve artistic elements of the design (such as negative space and asymmetry); wrapping copper wire tightly around branches to allow for the bending of these branches into positions that suit the design; “jinning,” or pruning in such a way that the pruned cut appears as a natural dead snag; and repotting, which reduces the root system to allow the tree to restore its original vigor. </li> Developing an understanding of design, which immersed me fully into the artistic side of horticulture, was the final concept. This included learning to analyze trees using the principles and elements of design, with a specific focus on space, balance, movement, form and unity. From there, it was a matter of learning to use the skills of pruning, wiring and repotting in order to make the starter material resemble a memorable tree in miniature. Most often this meant creating an environmentally driven form, or a tree that has been shaped by years of wind, snow, lightning and unfavorable placement. This only scratches the surface of design concepts within bonsai. </li> </ul> These skills culminated in the development of several of my own trees, from start to finish. The most remarkable of these was a Panchito manzanita (Arctostaphylos </em>× coloradensis </em>‘Panchito’) that I styled in the semi-cascade form, resembling a tree hanging horizontally from a cliff face. In addition to this, I gained experience through the restyling of a larger ponderosa pine, and through a project in which I was given the ability to choose which trees to present from the collection, and where to situate them within the pavilion for the appropriate emphasis, visual movement, variation and light requirements. </p> Although bonsai culture seems niche within the whole realm of horticulture, it has changed the way I think about plants and the interaction between art and science. While I am now certain my interest is in public horticulture, I hope to practice bonsai for years to come, whether as a hobby or an occupation. I’m incredibly grateful to have had this unique internship experience, and for the opportunity to connect and learn from top-tier horticulturists with a large diversity of passions and interests. </p> This post was written by Bonsai Collection Management and Curation intern J. Henry Basile,</em> a junior at Kansas State University studying general horticulture and minoring in Spanish. </em></span></span></p> </p>
As early as mid-April, migrating hummingbirds begin arriving in Colorado. Their presence is announced with the humming and whirring sounds made by their wings as they dart from flower to flower. At Denver Botanic Gardens these entertaining birds are commonly seen feeding on nectar and insects, aggressively protecting their territory, diving from the sky or checking out an unsuspecting visitor.</p> Indeed, Denver Botanic Gardens, with its diversity of plant species whose blooms span the seasons, provides an excellent stopover for migrating hummingbirds. As you take this tour, you will most likely be rewarded with the sights and sounds of these charismatic birds.</p> Now is the time to welcome hummingbirds with open flowers!</strong></p> Begin this tour at the Darlene Radichel Plant Select® Garden</strong> to see one of our earliest blooming shrubs: Arctostaphylos</em> × coloradensis</em> 'Panchito'. Facing Monet Pool</strong>, turn left onto the gravel pathway and look for a sprawling shrub on your right with thick, leathery, evergreen leaves. In the springtime, this plant has pinkish-white urn-shaped flowers that attract hummers. A Plant Select® native selection from the Uncompahgre Plateau, this cultivar will thrive in a well-drained area of your yard, where it will become a lovely evergreen groundcover and an early nectar source for hummers. </li> Next, head to the Gates Montane Garden</strong> to see another early bloomer, which is native to the Front Range. As you stroll through the shady forest, you may notice columbine (Aquilegia</em> spp.) and fireweed (Chamerion angustifolium</em>) in bloom, which are great mid-season nectar species for hummers. On your right, before you exit the Gates Montane Garden and where several paths converge with the main path, you will see wax currant (Ribes cereum</em>), a medium-sized shrub with maple-like leaves. In the springtime, it produces tubular, pale-pink flowers, which attract hummingbirds. If you are looking for a shrub with showier and more fragrant flowers, another wild currant that thrives in Front Range landscapes is golden currant (R. aureum</em>).</li> </ul> There are a host of showy mid-season-blooming species that attract hummingbirds</strong> including columbine (Aquilegia</em> spp.), scarlet gilia (Ipomopsis aggregata</em>), harebells (Campanula rotundifolia</em>), larkspur (Delphinium</em> spp.) coral bells (Heuchera</em> spp.), bergamot (Monarda </em>spp.), orange milkweed (Asclepias tuberosa</em>), Penstemon</em> spp. and Colorado Four O’clock (Mirabilis multiflora</em>). This tour features the latter two.</p> Exit the Gates Montane Garden and continue on the main path through the Rock Alpine Garden</strong>. Turn left on the path that divides the Upper Meadow from the South Ledge. About two-thirds of the way down, look for Colorado Four O'clock (Mirabilis multiflora</em>), which should still be in full bloom. This showy, drought-tolerant species has dark green leaves and lovely magenta flowers that attract hummingbirds. It is the perfect addition to Front Range landscapes – just allow enough space for it to grow!</li> Next, continue to Sacred Earth</strong>. You will be greeted with sprays of red, trumpet-shaped flowers amongst wispy grasses. These flowers belong to Bridges’ penstemon (Penstemon rostriflorus</em>), which is a later-blooming species of Penstemon</em>. Extend your red-blooming penstemon season with the early-blooming Eaton’s penstemon (P. eatonii</em>), followed by the mid-season scarlet bugler (P. barbatus</em>), followed by Bridges’ penstemon. While you are at it, why not add the early, pink-blooming desert beardtongue (P. pseudospectabilis</em>), a showy landscaping plant that is popular with hummingbirds in my yard.</li> </ul> Late Season Flowers for Hummingbirds: Send Hummingbirds off With a Nectar Party</strong></p> By early September, hummingbirds are heading south towards their wintering grounds. Fortunately, there are many late-blooming species that provide nectar for hummingbirds, including species of Salvia</em>, Agastache</em> and Epilobium</em>. The Roads Water-Smart Garden</strong> showcases examples of all three genera.</p> Once you reach the Water-Smart Garden, look for hummingbird trumpet (Epilobium canum</em> ssp. garrettii </em>‘PWWG01S’ ORANGE CARPET®) on your right. With its myriad showy orange-red flowers, you can’t miss it. Planted in your yard, it will quickly spread to form a ground cover that blooms from mid to late summer. And, as the common name suggests, this western nativar (native cultivar) is irresistible to hummingbirds.</li> As you continue through the Water-Smart Garden, notice the various species and cultivars of Salvia</em>. A favorite is Salvia greggii</em> ‘Furman’s Red’, which will be on your left. This species has crimson flowers that will bloom in the spring and then again through the fall. As you approach it, you will also see Agastache</em> on your left that is beginning to bloom.</li> End your tour with a walk along Water-Smart Garden’s gravel path, searching for various cultivars of both Salvia</em> and Agastache</em>. Notice how they are grouped with other drought-tolerant species including trees, shrubs, succulents and grasses to provide a textural and colorful landscape that is also beneficial for hummingbirds.</li> </ul> Once you have incorporated these plants into your garden, hummingbirds will come, although it may take time for hummingbirds to notice. When you hear the metallic whirring of a male broad-tailed hummingbird and watch it dart from flower to flower, you know your efforts have paid off!</p> In closing, it should also be mentioned that providing natural nectar sources in your yard is one important thing you can do for hummingbirds. However, hummingbirds also need water, shelter and space. To learn more, visit National Audubon Society’s website</a>.</p>
The Gardens’ mission is to connect people with plants. The actions we take in pursuit of that mission are guided by our core values, one of which remains especially relevant today: diversity. We have an incredible and obvious diversity among our plant collections, but we also strive for a diversity in the people we are connecting with those plants.</p> Unfortunately, contributions from members of underrepresented groups often lack visibility. In an effort to raise the voices of those struggling to be heard, we are highlighting some contributions that POC have made (and continue to make) in fields related to botany and horticulture in this monthly series.</p> Below are two African Americans whose focus on plants and the environment have improved, and even saved, the lives of many.</p> From the Past: </h2> Harriet Tubman (c.1820-1913), Herbalist</p> Harriet Tubman has gone down in history for numerous reasons, foremost among them being her role as a conductor on the Underground Railroad. But a skill largely unmentioned that aided her in roles as conductor, soldier, and nurse was herbalism. According to Leah Penniman, enslaved herbalists fought to keep their traditions at great costs; slave owners so feared being poisoned by the people they enslaved that herbal practices were banned altogether. Tubman used remedies passed down from her grandmother to treat fugitive slaves, keep babies quiet on the Underground Railroad, and heal soldiers in the Union during the Civil War. </p> </picture> </div> </div> </article> Harriet Tubman, National Portrait Gallery, Smithsonian Institution (c.1868)</span></span></span></p> Explore more!</h3> You can read about Harriet Tubman’s herbal skills and find Black herbalists from our own time in Leah Penniman’s book, “Farming While Black: Soul Fire Farm’s Practical Guide to Liberation on the Land” (Chelsea Green Publishing, 2018). Since our library is closed, we encourage you to support Black-owned bookstores</a> if you would like to purchase this title.</p> A powerful photo of Harriet Tubman was recently acquired through the joint efforts of the Smithsonian Institutions and the Library of Congress. It’s the only known photograph of Tubman in which she is a strong young woman (similar to her depiction in the woodcut image used in this post), in complete contrast to other images that were taken closer to the end of her life. You can read about the significance of this photograph – and see it for yourself – in this article from Smithsonian Magazine</a>.</p> Active Today: </h2> Majora Carter, Activist and Consultant</p> Majora Carter has dedicated herself to environmental justice, particularly for underserved communities. She found her passion before starting grad school, when a city plan to divert waste into her neighborhood (South Bronx) drove her to organize protests pushing for environmental awareness and a say in environmental policies. Recognizing the need for more and lasting change in the community, Carter founded Sustainable South Bronx in 2001 – a nonprofit focused on projects such as building green roofs and providing green job training and placement. She now heads her own consulting firm that advises clients on how environmental projects and policies can revitalize low-income communities.</p> </picture> </div> </div> </article> Majora Carter. Image s</a>ource</a>.</span></span></span></p> Explore more!</h3> You can listen to her 2006 TED Talk, “Greening the Ghetto”</a> in which she discusses more fully her work in the South Bronx.</p>
Now that it’s July and seedlings have had time to root in, container displays around the Gardens are taking off — bulking up in size, spilling over edges and launching flower stalks. Come with me as we wander among some of this season’s most colorful and dynamic displays. </p> First stop, the large containers outside the Bonfils-Stanton Visitor Center</strong>. Each pot is filled with citrus-colored flowers that echo the theme of neighboring beds – “So glad to see you,” a joyful hello to all who pass by. Although I chose the theme over a year ago, it has proven unexpectedly apt, reflecting the gratitude we feel welcoming visitors back. The highlight of this design is the tropical legume Senna didymobotrya</em> planted on either side of two cannas. Each plant has long stems that arch inward and, at distance, remind me of a person’s arms raised up in excitement before hugging a friend. Yellow, round flowers and leaves that smell like toasted corn give this beauty its common name, popcorn cassia. </li> Next stop, outside Marnie’s Pavilion</strong> where colleague Nick Daniels has transformed the low walls into a wondrous collection of cacti and succulents. This display encapsulates the principle that contrast is completion. It is diverse, unifying and satisfies our love of visual drama. Note how the variegated Agave attenuata</em> ‘AGAVWS’ Ray of Light pops in front of the brilliant red Aloe dorotheae.</em></li> From here we walk south to the Science Pyramid,</strong> where colleague Mike Holloway shows his talent for plant mixology -- combining cool and hot colors, spiny geometric forms and soft cascading ones. You’ll see more of his talents in the Victorian Secret Garden to the northwest, where kitsch is elevated to high art. Humorous touches — including a head planted with a bromeliad wig — are mixed with elegant combinations of foliage plants.</li> But first pass through the Steppe Garden</strong> to see an eclectic mixture of high-altitude gems displayed in front of the waterway. Colleague Sonya Anderson has assembled plants from four steppe regions, including a large pelargonium that looks like a tree and a king protea.</li> More must-see containers await in the Annuals Garden and Pavilion</strong>, where colleague Bridget Blomquist has lined beams of the pergola with baskets of silver dichondra, magenta geraniums and an Alternanthera </em>the color of red wine. The plants match those in planters below with equal lushness, making you feel as if you’ve escaped into a flower tunnel.</li> Next stop, South African Plaza</strong> where colleague Mike Kintgen transports us to the tip of Africa and nearby Madagascar and Sub-Saharan Africa. Here you’ll find flora that’s both familiar and unusual. Pelargoniums join lesser known specimens, such as Senecio </em>and Kalanchoe</em>, in pots on the terrace and in an adjacent bed of flowering torches, known as Kniphofia</em>.</li> Finally, walk through Le Potager,</strong> past a sea of larkspur to the gazebo and you'll find a container of Abutilon </em>‘Souvenir de Bonn’. Encircling it are wands of Campanula glomerata</em>, mingling so naturally with the flowering maple that you’d think they grew in the pot too. In fact, the campanula grows in the bed and the potted Abutilon </em>was placed there by colleague Ebi Kondo to create a seamless effect.</li> </ul>
Summer is officially underway. The cast of spring-blooming flowers we so eagerly awaited has been replaced by a rowdy and colorful mid-season crowd, who are having their day in the sun. And, while the initial excitement of the gardening season has not faded for many of us, reality has set in: weeds have proliferated alongside our beloved landscaping plants. Perhaps we were out of town for a couple of days, shifted our focus to a project other than our yards or needed a respite from the soaring 90°F temperatures. Meanwhile, weeds jumped at the opportunity, marched up and down sidewalk cracks and fence lines, colonized the darkest and most clay-heavy corners of our yards, and scrambled brazenly up desirable plants with their tendrils. </p> Some of these weeds are annuals or biennials that are easily addressed in an après-dinner weed-pulling session, accompanied with a beverage and snippets of conversations with friendly passersby. Pleasant enough. However, there’s that suite of more problematic weeds, perennials that reproduce vegetatively, creating clones of themselves until their radius expands. These are the weeds we pull repeatedly, only to become overwhelmed when they return with an exponential vengeance. One such weed is Canada thistle (Cirsium arvense</em>). </p> Identifying Canada Thistle</strong> A colony-forming species, Canada thistle emerges in the spring, punctuating yards (and other disturbed sites) with rosettes of leaves. Leaves are spiny lobed and from 4 to 8 inches long, mostly smooth and green above and white-woolly below. Around the time spring transitions to summer, a flower head emerges with one to five small pink to purple (rarely white) flowers. Fun fact: This species is dioecious, meaning individual plants have either female or male flowers. At maturity, Canada thistle stands 3 to 5 feet tall. What you don’t see is most of the plant—an extensive creeping root system that penetrates the soil to depths of 6 to 15 feet. </p> Since its arrival to North America several hundred years ago, Canada thistle has spread throughout much of Canada and the United States and is considered a noxious weed (list B) in Colorado. It aggressively competes with native plants, reduces crop productivity by vying for essential resources such as space, nutrients, light and water, is unpalatable to livestock and, if left to its own devices, can form monocultures in our yards. These are all compelling reasons to manage this species, but where to begin? </p> Research suggests that a combination of approaches works best for managing Canada thistle. Below are several suggestions: </strong></p> Mow frequently or cut back</strong> the rosettes with clippers </strong>from when the plant emerges in the spring through summertime. This will prevent flower formation and will also stress the plant by reducing carbohydrate storage in roots. </p> Glyphosate:</strong> From late summer up until the first hard freeze, spot treat by applying glyphosate to Canada thistle leaves using a paintbrush. The herbicide will be translocated to the underground parts of the plant, ultimately bringing about its demise. </p> Plant regionally appropriate plants:</strong> Once your yard’s thistle population is under control, plant regionally appropriate plants including a diversity of natives and Plant Select® plants. These require fewer inputs, including less fertilizer and water. Where bare ground remains, apply mulch. Covering bare ground with plants and mulch will make your yard less prone to future weed infestations. </p> Puccinia punctiformis</em>, a rust fungus that is host-specific and pathogenic to Cirsium arvense, shows great promise in managing Canada thistle populations.</strong> This biocontrol is currently being evaluated in Colorado for appropriate application timing and best methods. To learn more or to order, visit the Colorado Department of Agriculture’s Request-A-Bug</a> page.</p> Although Canada thistle is one of the more challenging weeds to manage, the good news is that with a multi-pronged approach over the course of several seasons, it is entirely possible to eradicate this weed from our yards. </p>
