What makes a plant “water smart”? There are plenty of plants that tolerate periodic drought, and many of them are old favorites that your grandmother probably grew: shrub roses, lilacs, oriental poppies, bearded iris and even hostas. These were classic mainstays of the traditional garden for a reason. While they may get a little stressed during dry stretches of weather, it doesn’t take much to get them through until the next good rain comes along, and they usually multiply enough to pass along to friends and neighbors as well.</p> But some plants just like</em> it dry, thriving in that spot that you thought was hopeless precisely because</em> it has lean soil and never stays wet for long. These are plants that would actually resent the frequent watering that most gardens rely on. The Roads Water-Smart Garden can go for weeks or months without any supplemental water, and this is in a hot, south-facing location against a building! It is never watered more than once a week during hot, dry weather and never more than a dozen times a year—often less.</p> There are dozens of real gems in this garden from arid regions around the world. Here are some of the stars:</p> Salvias</strong>: S. microphylla</em>, S. coahuilensis</em> and S. greggii</em> (hybrids and cultivars include ‘Wild Thing’, ‘Mes Azur’, ‘Furman’s Red’). These are loosely referred to as “autumn sage” and many other species and cultivars exist. Hailing from central Texas and throughout the Southwest and Mexico, these like plenty of sun and good drainage. Trim down to about 4 inches each spring and they will do the rest. Their vibrant colors will attract hummingbirds for months!</p> Wild buckwheats: </strong>The genus Eriogonum</em> is especially abundant in the western U.S., often favoring dry slopes and poor soils that other species find less appealing. Eriogonum umbellatum</em> is a variable native species. Its vast range (Alaska to Mexico!) results in many regional forms, and one of the best is from right here in western Colorado. The Plant Select®-honored ‘Psdowns’ KANNAH CREEK® grows as a short, wiry shrub with glowing lemon-yellow clusters of flowers in late spring into summer. Its dried rusty-hued flowers persist into fall and winter.</p> Penstemon</em>: </strong>This could be a long list, as this genus is at its best in the Southwest. A short “you must grow” list would include P. barbatus, P. pinifolius, P. grandiflorus, P. eatonii, P. pseudospectabilis, P. palmeri </em>– okay, there is no such thing as a “short” list of good penstemons! Using multiple species from the high, dry Southwest can extend your flowering season from May to October, in heights from 6 inches to 6 feet, and all these tubular flowers are irresistible to hummingbirds!</p> Delosperma</em>: </strong>Commonly known as ice plants, the hardy Delosperma</em> were unknown in cultivation until our own Panayoti Kelaidis began to experiment in the 1990s with an obscure purple species (D. cooperi</em>) from South Africa’s Drakensberg Mountains. Superbly adapted to Colorado conditions, they now come in a rainbow of colors and are a mainstay of xeric gardens across the nation. Several are scattered through the Roads Water-Smart Garden, but be sure to see the dazzling carpets of them in the Steppe Garden, Plant Select Garden and elsewhere. Standouts include Lavender Ice, GRANITA® Raspberry, and MESA VERDE®, all with shimmering flowers that nearly obscure the plants when in bloom.</p> Bulbs: </strong>This is a broad category, but so many are perfectly adapted to Colorado conditions that a few have to be highlighted. Those that thrive have a few things in common: They take advantage of abundant seasonal moisture, producing their leaves and flowers during our wettest season (April-early June). Their foliage dries out and disappears as our season gets warmer and drier. They all tolerate long periods of cold, dry conditions. Bold and colorful choices include foxtail lilies (Eremurus</em>), ornamental onions (Allium</em>) and the smaller “species tulips” and crocus—these are the original forms that most hybrids were developed from, and they are especially durable and resilient for many years in the right conditions.</p> Keep in mind that the Roads Water-Smart Garden alone has hundreds</em> of other species that create a year-round progression of color and texture, drawing on plants from similar climates around the world. The extended list would be very long indeed: Yucca</em>, Agastache</em>, Dianthus</em>, Acantholimon</em>, Ericameria</em>, Opuntia</em>, Hesperaloe</em>, Iris</em>, Arctostaphylos</em>, Sedum</em>, Lavandula</em>, Thymus, Papaver, Crambe</em> . . . you get the idea. This theme is echoed in the Steppe Garden, Dryland Mesa, Sacred Earth, the Laura Smith Porter Plains Garden, Plant Select Garden and parts of the Rock Alpine Garden. Visit us often to see what each changing season brings!</p> </p> Note: </em></strong>Not everything featured in this blog post or gallery is in bloom now, but should be throughout the month.</em></p> </p>
When their gardens are blanketed in snow, what do the horticulturists at Denver Botanic Gardens do? Well, for starters, they still garden! When the temperature is above freezing, our dedicated horticulturists are still pruning, removing plant debris and impeccably maintaining gardens for the coming spring. During the winter, horticulturists also expand their job descriptions immensely. Allow me to share just a few examples.</p> First and foremost, horticulture at the level we strive for requires meticulous planning and preparation. This consumes a large portion of a horticulturist’s time during the winter. They synthesize observations and data recorded throughout the growing season. Understanding how plants, design schemes and watering regimen affected their garden, they can continuously improve from each year to the next.</p> The horticulturists create comprehensive designs for every garden and order and propagate plants during this time to be ready for the first sign of spring. Horticulturists really tap into their creativity to try new plants, new designs or new planting techniques to keep Denver Botanic Gardens one of the best botanic gardens in the country.</p> The Gardens’ horticulturists here aren’t satisfied with only expanding their own knowledge. They take their expertise and share it with the Colorado community. This information is provided through symposia, conferences, classes, presentations and career fairs.</p> One of the best parts of this time of year is the ability for our staff to really work with other departments at the Gardens, such as education, research or marketing, to develop workshops, tours and interpretation to make a patron’s visit more educational and interesting.</p> Beyond all this, winter provides time for some very interesting work – plant exploration. Botanic gardens are first and foremost living museums of plants. We are constantly striving to expand collections, both for horticultural interest and conservation. Winter here in the northern hemisphere means the growing season in the southern hemisphere. It provides a great opportunity to observe plants in their prime and collect seed around the globe. During these winter months, while our plants lie dormant, we can collect and add more unique and interesting plants for you to see on your next visit! A few past trips we have undertaken in the southern hemisphere include plant exploration and collecting in South Africa, Lesotho and Argentina (Patagonia).</p> Now when the gardens are covered in snow and the horticulturists hard to find, I hope you have an idea of the work they are engaged in.</p>
For most, the word “evergreen” evokes the thought of a pine, spruce or fir tree. These are the trees that give year-round structure to our gardens and provide points to hold our attention and direct our focus. They are the forests that we cut for timber, paper and fuel. Without the dominance of the evergreen in the boreal kingdom we would surely have much poorer and colder lives.</p> While these giants provide much for us there are many other plants that share the designation and description of evergreen. To simplify and to broaden the term, evergreen means something that holds on to its photosynthetic tissue for at least a full year. Given this broader definition we can walk the garden in a new light of appreciation for evergreen plants.</p> From the moment you enter the Gardens you are greeted by a long hedge of our native Juniperus</em> </em>scopulorum </em>(Rocky Mountain juniper).</em> This scale-forming evergreen is many things to the O’Fallon Perennial Walk. It is the greenscreen before which a yearlong ballet of color and form dance. Its sheer height creates the illusion of a much larger, grander space. The rather formal specimens that comprise this hedge are nothing like what you would find growing tortured and wild in our adjacent foothills.</p> Moving past the perennial garden we encounter another structural wonder, but this time there is a splash of color and sense of delight and movement. The Romantic Gardens’ allée is created with Thuja</em> </em>occidentalis</em> </em>‘Yellow Ribbon’. Here in front of these glowing spires hundreds of couples have sworn sacred oaths.</p> Some sort or form of evergreen plant can be found in every garden on our campus but there is one garden that is themed just to showcase unique mutations in traditional evergreens. This is the Dwarf Conifer Collection. Most trees in this garden have some form of mutated, stunted or deviant growth habit and are clustered together to highlight how special and different these variants can be. Many of these plants have been collected in the Rocky Mountains and are grafted onto a “normal” root stock. Finding and propagating “dwarf conifers” is an entire industry in and of itself. Collectors from around the world come to study and evaluate these fascinating plants.</p> Up till now we have talked about mostly coniferous plants and how we associate them as having evergreen foliage. But another important group of plants can be seen on the east face of Dryland Mesa. The plants here are what we term broadleaf evergreens and their scientific name is Arctostaphylos.</em> These shrubs are very important members of our western flora and represent examples of species from Colorado and neighboring states. Most have round, thick, almost leathery leaves that have a soft green glow and are possibly best appreciated with a background of snow to accentuate the exfoliating rust-colored bark and the dancing green leaves. Wild and beautiful, these are specimens that are left largely untouched and allowed to grow to whatever form the local climate dictates.</p> The broadleaved evergreen Arctostaphylos</em> x coloradensis</em> has so many attractive qualities that staff member Larry Jackel has turned a rooted cutting of one into a bonsai. This selection blooms quite early and often goes on display in Marnie's Pavilion while in full flower in February.</p> A little farther on there is another example of a broadleaf evergreen. Used as a foundation planting and sculpted as a hedge, garden boxwoods (Buxus </em>‘Green Velvet’) are grown to create separation in the garden beds of Le Potager.</p>
With very few exceptions, January flowers are hard to come by in a Colorado landscape. Not so in the tropical plant collections at Denver Botanic Gardens. The Boettcher Memorial Tropical Conservatory, Marnie’s Pavilion and the Orangery are a perfect venue for your winter floral fix.</p> Clerodendrum </em>× speciosum</em> is a sterile natural hybrid that can be found in tropical regions of Africa. It’s hard to miss the bright orange flowers on this sprawling vine. Look closely and you’ll see that once the flowers have dropped, a bright purple calyx is left behind giving the impression that this plant is almost always in bloom. Look for this vine about halfway through the Tropical Conservatory on the south side.</p> A little further along the south path is a beautiful specimen of Dombeya elegans</em> – a hibiscus relative from southeast Africa. This plant is prized in tropical landscapes for its profuse winter blooms and it drought tolerance.</p> Cross to the north side of the Tropical Conservatory for a beautiful display from Heliconia orthotricha.</em> This species is native to Ecuador and naturally has many color variations. Ours is a bright mix of orange, red and yellow. You can’t miss it.</p> Exiting into Marnie’s Pavilion, take a moment to appreciate the powder-puff-like blossoms of Calliandra surinamensis</em>. In the wild, members of this genus cover a wide range. But as the name implies, Calliandra surinamensis</em> can be found growing wild in Surinam as well as other parts of northern South America. The colorful flowers of the legume attract nectar-feeding birds and butterflies.</p> You can finish your tour of blossoms in the Orangery where you can relax and enjoy the display of orchids in our annual Orchid Showcase, Jan. 10 – Feb. 17, 2019. Hundreds of blossoms will help you forget the worries of the day and plenty of benches are available for you to sit and decompress.</p>
</p> The holiday season is in full bloom at York Street as Blossoms of Light™</a> delights thousands of guests each night with mesmerizing displays of light and color. Though it is a tradition for many Front Range families, the new designs and features provide a new adventure every year for even the most seasoned visitors. In fact, CNN has ranked</a> Blossoms of Light as one of the top places to see lights in the entire country! </p> As you wander the lights, keep in mind that it takes a lot to get to this point! Here are some fun facts about Blossoms of Light that, if they don’t make you enjoy the lights even more, may at least shed some light (ha) on the scope and scale of this massive public event.</p> Blossoms of Light opened its first season of illumination over 30 years ago, in 1988.</li> Blossoms of Light is the Gardens’ largest single event of the year, drawing in more guests and revenue than any other.</li> It takes 13 months to design, plan, and execute the event. </li> Installation of lights begins on the Tuesday after Labor Day, and every light is removed by the end of February. Lights are installed with poles, lifts, climbing harnesses, waders and cherry-picker buckets.</li> Custom-strung lights are built by hand starting in early summer. Unusual light colors, such as teal or purple, must be ordered 6-8 months in advance because manufacturers only produce limited quantities each year.</li> We estimate there are more than half a million individual lights in the entire display. The exact number is very difficult to calculate!</li> 100 percent of the decorative lights used are LED.</li> Squirrels and wind are the biggest enemies to the lighting equipment.</li> The eagle-eyed visitor may notice that we double-dip in a few areas – we turn on some of the spookiest lights for Glow at the Gardens in October.</li> This is the first year in over a decade that we have extended Blossoms of Light more than a week past New Year's.</li> </ol> Tickets are selling quickly, so get yours before they are gone. We look forward to celebrating the season of light with you!</p> Blossoms of Light is open nightly (closed December 25) through January 16, 2021. Tickets must be purchased in advance. Get your tickets today!</a></strong></p> </p>
In part two of this series, we talked about carnivorous plants that use passive traps to catch insects and other small prey. Next, we cover the third and final trapping mechanism used by predatory plants — adhesive traps.</p> These traps can be divided further into the following categories: flypaper, fixed tentacles and mobile tentacles.</p> Flypaper Traps</strong></h3> Carnivorous plants with flypaper traps ensnare their victims with a sticky mucus that also acts as an attractant. Butterworts (Pinguicula</em> spp.) fall into this category. This genus currently contains over 80 species with new discoveries still being made in recent years. They can be found growing in native habitats throughout the northern hemisphere and southward into Central and South America. The richest species diversity can be found in Mexico.</p> Butterworts catch smaller insects such as gnats and fruit flies. These insects are drawn in by the sweet scent of the sticky nectar produced by the plant on short stalks attached to the leaf surface. Once the insect lands, it is unable to free itself and is digested on the leaf surface by a mix of digestive enzymes and acids secreted by the plant, with only their exoskeleton remaining as evidence of their demise.</p> These beautiful but deadly plants are beloved for their general ease of cultivation as well as their brightly colored flowers which range in color from white to yellow to scarlet red.</p> Fixed Tentacles</strong></h3> A second form of adhesive trapping mechanisms can be found in Portuguese sundew (Drosophyllum lusitanicum</em>) and rainbow plants (Byblis</em> spp.). These plants use a technique similar to butterworts to capture their prey, but the sticky mucus they produce is held further out from the leaf surface on fixed tentacles. This allows the plants to capture prey that is a bit further from their leaves and also larger in size than those caught by butterworts.</p> Portuguese sundew is unique from other carnivorous plants in that it is native to the relatively dry western Mediterranean regions of Spain, Portugal and Morocco. It can be a bit trickier to grow since it requires a faster draining soil media and more infrequent watering than its bog loving kin. The sticky mucus produced by this plant has a thicker, more resinous consistency than that of species found growing in boggy areas. This allows it to function better in the more arid conditions of its native habitats.</p> Rainbow plants are native to Australia and New Guinea, with seven species currently known to exist. Some are annuals and others are perennials. All live up to their common name, giving off a rainbow effect from their glistening leaves when struck by rays of sunlight.</p> Mobile Tentacles</strong></h3> Finally, the last example of adhesive traps can be found in sundews (Drosera</em> spp.), which have tentacles that move slowly to encompass their prey, smothering them in digestive enzyme-rich mucus. I love this quote from Peter D’Amato in his book, The Savage Garden: "If an insect ever evolved the brains to write a horror novel, the monster in that novel would probably be a sundew."</p> Sundews can be found growing on every continent but Antarctica, with the richest species diversity occurring in Australia. Over 125 species have been named in a wide range of forms, with many pygmy sundews staying the size of a small coin and other species like the South African king sundew (D. regia</em>) growing to over 2 feet tall.</p> If you are looking for a great carnivorous plant for beginners, the Cape sundew (D. capensis</em>) will be your best bet. Simply plant it in a mix of half peat and half sand, place it in a shallow saucer of distilled water in a sunny windowsill, and watch it catch any fly or fruit fly that dares to come near it. This plant seeds easily, and we often have seedlings available at our spring plant sale each year.</p> Butterworts and sundews can be found in the terrariums located at the east end of the Orangery. They can also be viewed during Free Days at the Gardens at the Carnivorous Plant Education table. Our Portuguese sundew lives in our aquatics greenhouse, where it has a steady supply of insects to keep it well fed. It can be viewed in some of our behind the scenes tours at the Gardens.</p> </p> For additional information about Carnivorous Plants, be sure to check out the International Carnivorous Plant Society’s website</a>. "The Savage Garden," by Peter D’Amato and "Growing Carnivorous Plants," by Barry A. Rice are both great books on the subject that offer more in-depth information about these amazing plants.</p>
From the moment your lungs take in that first breath of warm, comforting and humid air you know you have entered the Boettcher Memorial Tropical Conservatory. The Tropical Conservatory is home to over 550 species of plants spanning 306 genera from 87 plant families from all over the world. You have probably seen many epiphytes on previous visits but maybe didn’t know what they were. Read on and I shall cast some light on these wonderful oddities!</p> Epiphytes are organisms that grow on the surface of host plants, often attaching themselves with strong roots. They obtain moisture from the air and nutrients from debris around them. A common example of this would be Spanish moss (Tillandsia usneoides</em>) growing off of a tree branch. Epiphytes differ from parasites in that they attach only for physical support, not for food or water. They are found in every major group of the plant kingdom, including some species of algae growing under water. The Tropical Conservatory is host to many epiphytes, and they come in many different forms.</p> As you enter the Tropical Conservatory from the east end, take a few steps in and look up to the right. In a planter pocket of the rock ledge grows an exciting epiphytic orchid, Grammatophyllum speciosum</em>. Native to Indonesia, it is also known as the sugar cane orchid, because of the appearance of the pseudobulbs. The largest plant was recorded as weighing more than a ton and each raceme can bear up to 80 scented flowers. It can remain in bloom for up to 2 months.</p> Continue down the path, past the duck pond and up the stairs to the main level. From the top of the stairs turn right and look at the wall. Here you will see Platycerium bifurcatum</em>, or staghorn fern, mounted here. It is native to Java, New Guinea and southeastern Australia. They require consistent moisture and shady locations. It is widely cultivated as an ornamental plant. Its common name comes from the appearance of the dissected fronds.</p> The final plant on our epiphytic journey is an amazing silvery plant called Tillandsia tectorum</em>. It is found at the top of the treehouse, the highest point you can get to in the Tropical Conservatory. It has many thin, very silvery leaves and loves high light and heat. This plant is native to Peru and Ecuador. In late summer it gets a lovely light purple/pink bloom that can last for several months. This species is well suited to Colorado because of its love of low humidity and intense sunlight and makes a great plant for you to try at home.</p>
In the 1860s, pioneers settled on the land next to Deer Creek in what is now Littleton. The stream provided the settlers with the only water around for miles. Frank Hildebrand bought a log cabin and a large piece of land where he and his family constructed barns and other structures for their ranching business. Being in the arid grasslands up against the foothills, the Hildebrands understood that they needed to find a working relationship between the environment and their family farm. Their house, garden and summer kitchen were built near the creek to take advantage of the steady flow of water.</p> But building their structures near Deer Creek was a double-edged sword for the Hildebrands. The convenience of having close access to a vital resource was offset by the possibility of flooding caused by high-flow events. Our experts speculate that to mitigate the risk of flooding, the Hildebrands worked to channelize Deer Creek. Deepening the ravine and steepening the banks would increase the capacity for flow volume so floods could move through the system efficiently, causing less damage to the upper terrace and the Hildebrands’ livelihoods.</p> Today, the property is split between an open space park in Jefferson County and Denver Botanic Gardens Chatfield Farms. Hildebrand Ranch is on the National Register of Historic Places and many of the original buildings are still standing. Deer Creek is also an important wildlife corridor for bears, beavers, deer, coyotes, raccoons and many species of birds; however, channelized streams are not very productive for native species. Our conservation ecology team is developing a stream restoration plan that will find a balance between restoring the natural meanders of Deer Creek while also protecting the historical buildings on site.</p> This blog post was written by Margo Paces, M.S. student at University of Colorado Denver. Margo studies stream restoration along Deer Creek at Denver Botanic Gardens Chatfield Farms. She quantifies plant communities along the riparian corridor to gauge the effectiveness of restoration efforts.</em></p>
In part one of this series, we talked about carnivorous plants that use active traps to capture their prey. Next, we cover another trapping mechanism used by multiple species of predatory plants: passive traps.</p>While the active traps of Venus flytraps, waterwheel and bladderworts capture insects by either snapping shut on them or quickly sucking them in, passive traps do not use any motion to catch their prey.</p>These inactive traps can be further broken down into “pitfall,” “lobster pot,” and “pigeon” traps.</p>Pitfall Traps</strong></h3>Modified leaves are used as individual pitfall traps by many types of pitcher plants, including hardy, tropical, Australian and sun pitchers. Hardy pitcher plants (Sarracenia</em> spp.) can be found growing in nutrient poor bogs throughout the United States and into portions of Canada, while tropical pitcher plants (Nepenthes</em> spp.) are natives of Madagascar, Australia and Southeast Asia. Sun pitchers (Heliamphora </em>spp.) are native to swampy areas on high plateaus in South America, specifically Venezuela, Guayana and northern Brazil. Australian pitcher plants (Cephalotus follicularis</em>) consist of a single species which can be found growing in swamps or alongside streams and creeks in southwestern Australia.</p>Pitfall traps often have a nectar producing portion near the entry of the trap and may also be brightly colored. Both features aid in luring insects. Downward-pointing hairs can often be found inside these traps, which make it easy for insects to crawl in but much more difficult for them to get out. Some of these pitfall traps have liquid in the base which contains digestive fluids produced by the plant. Others do not have a pool of water but exude digestive enzymes once the insects starve in the trap. Some large species of tropical pitcher plants have even been known to draw rodents into their traps!</p>Lobster Pot Traps</strong></h3>One hardy pitcher plant that uses a slightly different passive trapping mechanism is the parrot pitcher plant (Sarracenia psittacina</em>). The method of trapping used by this species is referred to as a “lobster pot” trap and encourages insects to crawl deep into a trap with the lure of nectar. Once inside, the bug is confused by the presence of glassy windows, known as areoles, which allow light into the trap. It cannot find its way out through the darker trap opening and is slowly digested by the plant.</p>California pitcher plants (Darlingtonia californica</em>), which are native to a small range in northern California and southern Oregon, also use these types of traps in combination with a pitfall trap. Insects are drawn to the mouth of the trap by the sweet scent of nectar. The pitcher is lined with areoles, which allow light into the trap, confusing the insects. It becomes easier for the bugs to find their way further into the trap then to find a way out through the darker opening, and they eventually reach a portion with slick, downward-pointing hairs—the pitfall portion of the trap. Unfortunately, it is all downhill from there for the insect—both figuratively and literally.</p>Pigeon Traps</strong></h3>The final type of passive trap used by carnivorous plants can be found in the multiple species belonging to the genus Genlisea</em>, commonly referred to as corkscrew plants. Native to Central and South America as well as Africa, these plants grow in aquatic or semi-aquatic habitats and feed mostly on protozoans. Researchers are still studying how prey are drawn into the plants’ traps, but once there, the trap uses a technique also used in pigeon traps. Prey push past inward-pointing hairs as they enter the trap, which prevent them from backing out.</p>At the Gardens, you can see examples of carnivorous plants with passive traps in the terrariums located at the east end of the Orangery. Sun pitchers live in two of these terrariums and hardy pitcher plants are often rotated into the displays during the summer months. A tropical pitcher plant (Nepenthes alata</em>) can be found in the largest terrarium, while other Nepenthes</em> species can be viewed through the glass panels which divide the Orangery from the easternmost greenhouse.</p>In the third and final part of this series</a>, we will examine carnivorous plants that use sticky “flypaper” type traps to capture their prey.</p>
