Conservation of rare species involves knowing where they are found and how many individuals are in a population. If a species can only survive in certain habitats, then any changes to that habitat can drive a species to extinction. Similarly, as the population size decreases, chance events can have an increasing impact. </p> A rare cactus found only in western Colorado has recently been recommended for delisting from the Endangered Species Act because we know more about its natural history now than we did at the time of listing. We have a clearer understanding of how much genetic diversity is present within and among populations (enough to propose naming a new species). We know more about how survival, growth and reproductive rates drive population size (pretty stable). Lastly, and maybe most importantly to this decision, we have better estimates of the number of individuals in each population (many more than previously documented). Estimates of the minimum cactus abundance provide a snapshot of the current status and show that population sizes are large enough to persist through random fluctuations in germination and reproduction. </p>
Architectural plants provide a visual structure and framework as well as a year-round presence in the garden. Plants don’t have to be woody to lend structure to the garden; perennials, grasses, evergreens and shrubs offer not only visually engaging elements but also provide habitat for pollinators and animals in all seasons. Let us explore the Gardens to see examples of architectural plants. </p> </p> Yucca rostrata</strong></em> </a></h3> As you approach the Crossroads Garden</strong>, you cannot miss this specimen. A striking plant that gives a strong sense of place, Yucca rostrata</em>, or beaked yucca, provides a structural integrity that remains throughout the season and only becomes more outstanding over time. It takes years to establish a “trunk” but is well worth the wait. Yuccas grow in many parts of the U.S. but are often identified as a “western” plant seen in drylands and deserts. Almost all yuccas bloom prolifically in spring offering the bonus of showy flowers held high above their foliage. Yuccas require well-drained soil and full sun. </p> Picea glauca</em> ‘Pendula’</strong></a></h3> Flanking either side of the Roads Water-Smart Garden </strong>entrance in the raised planters, Picea glauca</em> ‘Pendula’, weeping white spruce, immediately communicates elegance and grace. Narrow and upright, this is a great choice for small spaces or as a specimen plant in the garden. Provide plenty of sun and moderate water. Available through Plant Select®</a>. </p> Juniperus scopulorum</em> ‘Woodward’</strong></a></h3> Columnar Woodward juniper creates a distinctive framework along the walk next to the UMB Bank Amphitheater</strong> and Roads Water-Smart Garden</strong>. This plant resembles the columnar Italian cypress, making it an elegant choice for entrances and corridors. Junipers are tough plants that withstand just about any growing conditions. Best in full sun and once established require little to no maintenance. Woodward juniper is a Plant Select specimen that works great as a screen in tight spaces. </p> Agave parryi</strong></em></a></h3> Another “western” plant which provides character and structure is Parry’s agave. This coarse-textured evergreen is incredibly tough, requiring full sun and very little water. These are slow growers, but they live up to 30 years. They bloom at the end of their life cycle – a sight which cannot be missed. The flower stalk can be up to 12 feet high above the rosette. But don’t worry, before they flower, agaves produce vegetative offshoots, also known as “pups,” which can be easily transplanted and propagated to become mature plants. </p> Ornamental Grasses: Schizachyrium scoparium</em></a>, Sorghastrum nutans</em></a> and Calamagrostis brachytricha</em></a></strong></h3> Many ornamental grasses perform extremely well in our steppe climate. The Ornamental Grasses Garden </em>showcases these versatile, low-maintenance plants. When left up in the winter, not only do grasses provide structure but also movement and color. There are many to choose from, including little bluestem, Schizachyrium scoparium</em>, which turns bronze to burgundy in fall. If you want a unique grass in your garden, try Sorghastrum nutans</em>, Indian grass. Its similar size and upright habit make it a great alternative to feather reed grass (Calamagrostis</em> × acutiflora</em> 'Karl Foerster'). Even shady gardens can utilize ornamental grasses. Korean feather reed grass (Calamagrostis brachytricha</em>) is a Plant Select selection that is drought and (part) shade tolerant! </p> Perennials: Stonecrop (Sedum spectabile</em>)</a>, yarrow (Achillea)</a>, Jerusalem sage (Phlomis russeliana</em>)</a>, globe thistle (Echinops ritro</em>)</a></strong></h3> Flowers and seed heads, though their color has faded, create texture, winter interest and habitat for plants and pollinators! A walk through the Romantic Gardens </strong>offers several examples of perennial winter interest. Around the circular water feature, look for sedum and yarrow, classic winter perennials in the garden. Caryopteris</em> × clandonensis</em> 'Worcester Gold', also known as bluebeard, is only half hardy in our climate but it must be mentioned as it provides great winter interest and is an incredibly tough and beautiful flowering plant. </p> Enter the Fragrance Garden</strong> and along the curved walkway, look for dried flowers stacked vertically on stems. These are Jerusalem sage, or Phlomis russeliana</em>, and holds blooms and stalks well throughout the winter. Turning left at the gazebo next to the benches in El Pomar</strong>, look for rounded seed heads on globe thistle (Echinops ritro</em>). All have unique flower heads that stand tall and remind one of what is to come in spring.</p>
If dried flowers make you think of withered Miss Havisham and her decaying wedding dress, then it’s time to raise your expectations. Today’s dried flowers are nothing like the faded flowers worn by the jilted bride of Charles Dickens’s “Great Expectations.” They’re boldly combined, lushly textured and even colorful.</p> So, what’s changed? The floral industry has embraced dried plants as it’s pivoted to become more sustainable. When locally sourced and kept natural (not bleached or dyed), dried flowers have a smaller carbon footprint than fresh flowers that are flown in from overseas, refrigerated and displayed in non-biodegradable floral foam.</p> This has led to a surge in creativity. Floral artists are pushing the boundaries of display – adding dried flowers to fresh and wiring dried plant material to everything from hair combs to chandeliers. They’re also preserving flowers that were rarely dried before, from peony blooms to Smoke Bush plumes, and combining them in ways that take them beyond ordinary.</p> Consider the brown fronds of dried leatherleaf fern. Alone they may look ho-hum, but when spiraling around the edge of a wreath filled with Honesty seed heads and Chinese Lantern pods, they create energy. Or the fluffy heads of Pampas grass. By themselves, they could pass as feather dusters, but when wired with dried roses and allium seed heads onto chandeliers, they’re positively ethereal. </p>
Seeds are quite amazing little capsules of information; it is mind-boggling that something that fits in the palm of your hand (or on the tip of your finger) can hold the information needed to grow something as large as a tree! Not only do seeds act as a container of genetic information but they also contain mechanisms to make sure that the embryo will start growing exactly when conditions are just right for it to thrive, even if that means waiting for years to get it right.</p> While seeds “wait” to germinate at the right time in the right place, they will go into types of dormancies to help preserve the information it contains inside. As gardeners, we strive to manipulate environments so they’ll grow when we want.</p> </p> Here are a few simple tricks I have learned over the years:</h3> Cold stratification</h4> Seed dormancy can be regulated by the environment or by the seed itself. In Colorado where we experience a temperate climate (which generally have wider temperature ranges throughout the year with distinct seasonal changes), many plants are used to a cycle of blustery, winter temperatures followed by the fluctuations that spring, summer, and fall bring about.</p> We can mimic this through a period of moist, cold stratification. At the Gardens, we sow flats of seeds, water and cover them up and either place in a cooler or outside in cold frames in winter. At home, you can do the same by either placing seed in wet sand or vermiculite in a baggy and storing in your fridge or freezer until you are ready to sow. Alternatively, you can take advantage of our spring snowstorms and broadcast seed directly into your garden just before an expected snow to let seeds get a taste of real winter. </p> </picture> </div> </div> </article> Sophora secundiflora</em> (Texas Mountain Laurel) having germinated after scarifying the seed and a short cold stratification. </p> Scarifying</h4> Many seeds (think tree seeds and legumes) have a thick, tough seed coat protecting the seed until prime conditions occur. Scarifying, or mechanically breaking down the seed coat, can also give you a higher percentage of germination in a quicker process than mother nature does. The goal is to expose the tender tissues hiding inside; this can be done several ways and you can get creative in the process. In our greenhouse workspace we have several tools to scarify, including sandpaper, nail files and clippers, and even needles to poke and nick. </p> </picture> </div> </div> </article> Cacti seed with the seed coat being chipped off with a needle to expose the tender tissues inside. </p> Water baths</h4> Soaking your seeds in water is another simple trick to germination. Soaking in water can either help soften the seed coat to wake up the hiding embryo or can leach out chemicals in the seed coat that are preventing germination until conditions are right. A technique I have fallen to recently is an aerated bath, where seeds soak in a bath of water being turned by an aquarium air pump which provides required oxygen to the seeds as their coats soften. </p> </picture> </div> </div> </article> Seeds in an aerated soak having germinated in the bath, before sowing. </p> </p> Breaking seed dormancies can take a little expertise (and time) but it’s so rewarding once the deed is done! </p> This article first appeared in the February edition of Life on Capitol Hill. All images: Brooke Palmer. </em></p>
When I was in school, one of the fun things I learned was how to identify trees and shrubs in the wintertime without seeing blossoms and foliage. Since the deciduous woody plants dropped their leaves in their dormancy, we at first thought that there were less clues to identify the plants. However, we found out that there are many clues (more than we thought!) available in the wintertime even though the plants look bare.</p> Shape of trees and shrubs</strong></p> Each kind of tree and shrub has own growing habit. </p> Elm trees (Ulmus</em> spp.) and linden trees (Tilia</em> spp.) tend to grow upright and develop an elegant "vase shape."</li> Hawthorns (Crataegus</em> spp.) and crabapple (Malus</em> spp.) grow rather horizontally.</li> Some tree and shrub branches have a straight growing habit, but others have a weeping form or a slightly more jagged shape.</li> </ul> Bark</strong></p> The texture and color of bark can be a good clue to narrow down and identify the plants.</p> The cherry tree (Prunus</em> spp.) and crabapple (Malus</em> spp.) often have reddish smooth bark compared to ash trees (Fraxinus</em> spp.) and silver maple (Acer saccharinum</em>), which have greyish ribbed bark.</li> Weeping birch (Betula pendula</em>) and paper-bark maple (Acer griseum</em>) have a uniquely characteristic shredded bark.</li> </ul> Twigs</strong></p> One good clue is to take a closer look at twigs to see how the buds are forming.</p> If the buds are arranged in pairs along a stem or shoot, it’s called "opposite"</strong> such as maple (Acer </em>spp.), ash (Fraxinus</em> spp.) and horse chestnut (Aesculus hippocastanum</em>).</li> If the buds are forming singly on alternate stems or shoots, not in pairs or whole, it’s called "alternate"</strong> such as crabapple (Malus</em> spp.), hawthorn (Crataegus</em> spp.) and oak (Quercus</em> spp.).</li> </ul> Buds</strong></p> Take a closer look at buds to see their shape, color and detailed parts.</p> Notice pointy buds (serviceberry, Amelanchier</em> spp.), round buds (oak, Quercus</em> spp. and ash, Fraxinus </em>spp.) and hairy buds (magnolia, Magnolia</em> spp.).</li> The bud scar of white ash (Fraxinus americana</em>) looks like a smile as it curves, but the bud scar of the green ash (Fraxinus pennsylvanica</em>) is straight, not smiling.</li> In January to early February, you can often find dark, maroon-colored blooms of silver maple (Acer saccarinum</em>) on the sidewalk as squalls and birds pick them from the twigs.</li> </ul> Fruits</strong></p> Seed pod: (Kentucky coffee tree, Gymnocladus dioicus</em>, desert willow, Chilopisis linearis</em>, catalpa tree Catalpa speciosa</em>)</li> Samara: dry-winged seed, either single like that of the elm, or double like that of the maples (Acer </em>spp.)</li> Capsule: a dry seed pod that split open when ripe such as burning bush (Euonymus alatus</em>)</li> Catkin: A dense spike of small, petalless, often unisexual flowers, most often found on wind-pollinated trees or shrubs such as mountain alder (Alnus incana</em> spp., tenuifolia).</li> </ul> </p> Good luck with your investigation while you are walking around the Gardens on a nice winter day!</p>
Greetings friends of the Gardens, I hope this article finds you well. I would like to formally invite you all to come experience the newly renovated Cactus and Succulent House located in the Rock Alpine Garden. Starting your step count from the edge of the Bonfils-Stanton Visitor Center and into the Gardens it will take about 575 steps to get to the front door of the Cactus and Succulent House. Assuming you like succulent plants as much as I do, I suggest you make no other stops on your way as you perform your own individual step counts while also anticipating the awaiting beauty. </p> I took over the care of this collection in October 2020 and began making preparations and plans to refresh excitement of this public display and put these plants in a more naturalistic setting. Most of the more than 215 species located here are frost tender and prefer high light. This collection highlights the range of sizes, shapes and colors available in succulent plants. One of the many reasons you should not wait to see this display is the fact that most of the species from Africa are much more active in growth and flowering during winter months while the outdoor gardens sleep.</p> A few of the more notable specimens include a large-branched Alluaudia procera</em>, endemic to south Madagascar. It is a member of family Didiereaceae. Researchers have yet to figure out where this plant family originated. Alluaudia’s</em> leaves are produced from brachyblasts, a specialized structure that mimics a cactus areole. </p> Another interesting specimen is the Tim Burton-like Ceropegia stapeliiformis</em>. Undoubtedly one of the coolest flowers in existence, this sprawling, cylindrical plant is native to South Africa. Guests of the Gardens can expect to be delighted with flowers from March – October.</p> A plant that was not collected for use in cultivation until the early 2000s is the miniature gem Crassula ausensis</em> ssp. titanopsis</em>. It is native to southern Namibia and has become a staple in succulent collections.</p> One of the most eye-catching plants in this display is the zany, wild and strange Albuca spiralis</em>. It is a bulb from South Africa and has many different forms in the plant trade. One can’t help but bask in the natural beauty of this species. It goes dormant in the summer months shortly after flowering, and the soil needs to be kept on the dry side.</p> I hope you enjoy the new cacti and succulent plant display when you visit us this year!</p>
