In mid-February a group of Denver Botanic Gardens supporters and I began an exciting journey to Peru, spending time in each of the three major climate zones – the coastal desert, mountainous Andes highlands, and the rainforest of eastern Peru. Over the next several weeks, I will present highlights from this trip, sponsored by Denver Botanic Gardens and Reefs to Rockies Travel. We begin our adventure in Peru’s capital city, Lima. Located on the Pacific coast in a coastal desert climate, Lima is a large city of nearly 9 million people (almost one third of Peru’s total population). I was impressed with the cleanliness of the city and the many beautiful parks and boulevards throughout the area. Our first scheduled activity was a visit to the Larco Herrera Museum – a wonderful museum dedicated to Pre-Columbian Peru. Exhibits are arranged chronologically and include hundreds of artifacts, some over 3000 years old. The ceramics were particularly interesting, especially the many beautiful examples of Whistling Vessels (Ceramic jars with two openings - when water is poured from one opening, air rushes in the other and creates a whistling sound.). Ulla, our enthusiastic and passionate tour guide, did an incredible job of describing the significance of the shape of and decorations on all the various jars. Textiles were also well represented. An important advancement in textiles came with the full domestication of cotton around 1000 BC. Cotton provided stronger fishing nets and therefore a more reliable source and amount of food. Hunters and gatherers were gradually replaced with fishermen - allowing the development of the first commercial centers along Peru’s coast. The museum also has many beautiful examples of ceremonial textiles. I particularly admired a brightly colored blue and gold “standard” or flag that was found buried in a clay jar in a dessert in southern Peru. It is believed to date from between 800 and 1300 AD. It was only upon closer examination that I saw how the colors were created - each block of color was made up of thousands of small blue or gold macaw feathers. After far too short a stay, we loaded onto our bus and headed off to see the Barbosa-Stern art collection. We were given a tour of this private collection of Viceregal art by Sylvia Stern and her son, Aldo Barbosa. The tour was very enlightening, showing how early European settlers (mostly Spanish) influenced art in the region. Especially interesting was the use of art by the Catholic Church to persuade the Inca to convert to Catholicism. Our hosts helped interpret the symbolism in the paintings (many on copper or tin “canvases”) and explained how images were adapted from European standards to be more relevant to the Inca culture. For example, instead of the camels you might see in a European painting, the early religious paintings in South America might have shown a llama or alpaca. Angel wings often had bright colors – suggesting condor or parrot feathers rather than wings of a dove. Perhaps one of the most famous examples of this regional adaptation is a painting by Marcos Zapata in the cathedral in Cusco. This rendition of The Last Supper shows Jesus and his disciples dining on Cuy (Guinea Pig) and partaking in a glass of Chicha – a local “beer”. We finished our day in Lima with dinner at Casa Aliaga – the oldest colonial mansion in Lima. The home was built on land given to the Aliaga family by Franzisco Pizarro in 1535 and has been inhabited by descendents of the Aliaga family ever since. We enjoyed a short presentation on Andean flora and then a wonderful meal including lucama custard drizzled with chocolate – a favorite local dessert. After an exhausting day, we returned to our hotel to prepare for an early flight the next morning. I don’t think any of us had trouble sleeping – except for the short interruption by a 4.2 earthquake!</p>
About this time each year I start itching to see the first blooms of spring. Thankfully, the Orangery at Denver Botanic Gardens is currently loaded with colorful orchid blossoms. Come visit our Orchid Showcase to help quench your thirst for that burst of spring color. Our Orchid Showcase (which runs through February 20th) features hundreds of orchid plants in full bloom artfully arranged throughout the entire Orangery. The colorful blossoms are complimented by exotic bromeliads and other lush tropical foliage as well as citrus trees – many of which are also currently in full bloom. Between the scent of the citrus blossoms and the bright colors of the orchid flowers, it’s easy to forget that it is still winter. Unless of course it is snowing outside – but this only makes the warmth and coziness of the Orangery all the more enjoyable. If you’d like to learn a bit more about growing orchids, we are also offering free orchid repotting demonstrations each Saturday and Sunday afternoon at 12:30. Just drop by Marnie’s Pavilion and a Horticulture staff member will be on hand to help ease any anxiety you may have about repotting and caring for orchids. The Orangery at the west end of the greenhouse complex has quickly become one of my favorite new spaces at Denver Botanic Gardens. Sitting on a comfortable garden bench surrounded by beautiful lush plant life is especially enjoyable on a cold winter day. It’s not often you can enjoy hundreds of orchid blossoms interspersed with blossoming citrus trees juxtaposed with snow covered pines just a few feet away. I hope you will find time to pay a visit soon.</p>
</p> There are a number of plants that are clever enough to bloom during the winter months: none more predictably, nor beautifully, however, than the ill-named Christmas rose (Helleborus niger</em>). There are a few selections of this species that often begin to bloom in October or November most years, and yes, these may happen to be in bloom for Christmas. But invariably by January, I always have a few of these huge, waxy white flowers opening in my home garden. Mike Kintgen reports that they are blooming in the Rock Alpine Garden right now, and likely in one of the many other gardens where these are planted at Denver Botanic Gardens.</p> </dt> Helleborus niger at Denver Botanic Gardens Waring House, March 2011</dd> </dl> So why not call these "New Year Roses"? a more apt and accurate name...oh well. Fat chance. Christmas has a stranglehold on the name. There is a whole industry in Europe cranking out Christmas cards with paintings of these lovely plants. I'm sure there have been tens of thousands of these over the years. I love the thick, leathery leaves, with their lyrate pattern almost as much as their blooms. The foliage makes a wonderful evergreen fountain of color year around, and make a graceful setting for these enormous flowers. I have seen these nearly 3" across in some forms: the petals are thick and waxy and simply gorgeous. Some age a deep rose red. It will bloom through thick or thin (and we are sure to have some very cold weather still) for the next three months: a marathoner if there ever was one! There is an enormous amount written about this plant in books, magazines and the web: worth browsing. It has accumulated great herbal lore (don't try it, though: it's very poisonous!), and a great deal of myth. I finish by saying that it loves Colorado, and should be planted by everyone here. Give it a good loam, enriched with a bit of humus in part shade. Don't let it dry out too much (especially the first year as it establishes). Once established in the right spot, this is quite tough, even somewhat xeric and likely to last in the garden for the rest of your life! (You can't say this about many herbaceous plants)...There are a wealth of hybrids of Christmas rose becoming available, not to mention a veritable revolution occuring with Lenten Roses: these, however, are mere distractions and side shows as far as I'm concerned: this is the Queen flower of winter. Let us bow down in wonder and worship! (I do anyway).</p>
From time to time, the greenhouse team at Denver Botanic Gardens will build hypertufa troughs. These troughs are a great addition to a garden, especially for showcasing some of the rock garden plants, native wildflowers, and cacti that might otherwise be lost in a larger landscape. We sell our planted troughs at the Spring and Fall Plant Sales and occasionally throughout the season at the Shop at the Gardens. However, if you are interested in making your own hypertufa troughs, I would like to share with you our process and recipe for making a simple hypertufa trough.</p> </p> Supplies</strong></p> For this project, you will need the following supplies:</p> Portland cement (either white or gray--if you are using a dye, the color of the cement will effect the dye)</li> Vermiculite</li> Sphagnum peat moss</li> Concrete dye</li> Synthetic concrete reinforcement fibers</li> A plastic mold, such as a large bowl, a cat litter tray or a dish pan</li> 1mm or thicker plastic sheeting (this can be a thick trash bag, a painting drop cloth, etc.)</li> Water</li> </ul> </p> Where to get supplies</strong></p> In the Denver area, most of these supplies are readily available. The peat moss and vermiculite can be found at most garden supply centers or at a large retail horticulture products supplier. The Portland cement, concrete dye and synthetic reinforcement fibers can be found at any specialty concrete supply store.</p> Supplies prep</strong></p> The task that will take you the longest in your trough making endeavor is the materials prep. The cement and vermiculite can be used as is. It is advised that the peat moss be sieved to remove large particulates and to provide a smaller grain material. However, if your goal is a coarser appearance, the sieving is not necessary.</p> The materials that take the most prep time are the synthetic fibers. When they are purchased, the fibers have the appearance of clumps of white strings. The fibers are added for stability and need to be consistent throughout the batch. To obtain this consistency, the fibers need to be ‘fluffed’ before they can be added to the mixture. This can be done by rubbing the fibers between your fingers until they take on the appearance of a pile of cat hair. It can be quite time consuming, but definitely worth the effort.</p> </p> Tools</strong></p> Dust mask</li> Rubber gloves</li> Wire brush</li> Propane torch</li> A bucket or container for measuring your dry ingredients</li> Wheelbarrow or suitable container for mixing the hypertufa</li> </ul> Mixing the hypertufa</strong></p> Once you have obtained and prepped your materials, it is time to mix the dry ingredients. It is advisable to always wear a dust mask and rubber gloves when working with Portland cement. We have experimented with several recipes; the following recipe is our favorite for strength and appearance:</p> 2 parts Portland cement</li> 3 parts vermiculite</li> 3 parts peat moss</li> 1-2 cups of dye (depending on the color you are hoping to achieve)</li> 3-4 cups of ‘fluffed’ synthetic fibers (this will translate to about a 1/4 cup unfluffed fibers). These fibers will not be added to the dry mixture; rather, they will be mixed in as you are adding water.</li> </ul> The size of the trough (or troughs) you are hoping to obtain will determine the amount of hypertufa you mix. If your goal is to make one small trough, the bucket you are using to measure out your ‘parts’ should reflect this size.</p> </p> Once you have mixed up your dry ingredients in the wheelbarrow/mixing container, it is time to add water. It is important to only add a little bit of water at a time; if your mixture becomes too wet, the end result will not resemble hypertufa. If you have a partner to aid in this process, the extra set of hands will be very helpful. While one person is using a shovel to turn the mixture, the other person can be incrementally adding water and synthetic fibers. This is also a good time to make any adjustments to the color of the mixture by adding more dye, if necessary. The desired result is a mixture that when squeezed in your hand both holds its shape and releases just a few drops of water. If you squeeze the mixture and it feels squishy or you can visibly see a lot of water forcing out, you have added too much water.</p> </p> Filling the forms</strong></p> Now that your mixture is ready to go, it is time to start making the trough by adding the mixture to the form (the plastic container) that you have chosen. As you will have to cover the finished project later with the plastic sheeting, it is a good idea to lay the sheeting down before you begin the molding process. As this is also a bit of a messy project, the sheeting will protect whatever surface you are working on.</p> In general, regardless of the size of your trough, you want the walls and bottom to be between 1-1/2 - 2 inches thick. Begin by adding shovelfuls of mixture to your form. This mixture needs to be compacted (to form the base) either by pushing with your hands or using a block of wood to push it down. If you do not compact the hypertufa, as it dries it will form holes in the trough and will generally lose stability.</p> As you are forming the base, start working your way of the side walls of the form. If the walls of your form are somewhat steep, it may be difficult to compact the mixture against the form. If this is the case, you can try compacting the mixture in your hands and then apply it to the inside of the form.</p> As you continue to build the walls of the trough, remember to keep the thickness consistent. It is very important that you make a drain hole in the bottom of your trough. If the trough is larger, you may want to make two or three holes. This is the best time to make the hole; if you forget, it will be necessary to drill it out once the trough has dried.</p> Curing</strong></p> Once you have molded the hypertufa in to the form and you are happy with the way it looks, it is time to begin the curing process. This is a two stage process; the first part lasts between 24-48 hours and the longer curing should take about four weeks.</p> Immediately after finishing the molding process, you will cover the trough with the plastic sheeting. Between 24 and 48 hours you will remove the trough from the form and leave it under the plastic sheeting. When to remove the trough is determined by the hardness of the mixture. If you can scratch it with your fingernail, it probably needs about 12-20 more hours. If you need a screwdriver to scratch the surface, this is about the right hardness. In general, smaller troughs take longer to cure than larger ones.</p> To get the desired appearance for your trough, this is the time when you would use the wire brush to rough up the outer surfaces of your trough. Most likely the plastic form will have left the trough looking shiny and smooth. Typically, hypertufa troughs have a rough and more weathered appearance. The wire brush will help you alter the texture to your liking. To make the trough as strong as possible, the longer curing method is recommended.</p> Once you have removed the trough from its form and altered the texture, place the trough back under the plastic and keep it at room temperature for four weeks. You will want to occasionally check the trough to make sure it is not drying out. If it feels dry, moisten it with water. After the curing process, if all goes well, you are ready to plant your trough! Remember to use well-draining soils and chose plants that are suitable for troughs.</p> </p>
My name is Dan Auerbach and I’m from Philadelphia, PA. I have one year left at Temple University to earn my bachelor’s degree in horticulture. I was fortunate enough to receive the Propagation, Production and Seed Herbarium Maintenance Internship at Denver Botanic Gardens for the summer.</p> I have visited Colorado several times before, but had never been to the Gardens. The Gardens is incredible, and my first impression was that it all seemed too good to be true. Ten weeks of horticulture at one of the most prestigious botanic gardens in the world! I was excited, but still unaware of the full scope of experiences that I was in for.</p> My horticultural mentor, Senior Horticulturist and Head Propagator Katy Wieczorek, filled me in on the details of the project I would be working on for the summer. It was extensive and had multiple components but can be generalized as a seed germination experiment dealing only with native Colorado species. I would be researching and evaluating the effects of seed pre-treatments on germination.</p> I began by selecting over 180 native Colorado plant species that the Gardens currently had seed of. These species were selected based upon several conditions: plants that had previously existed in the Gardens, are currently in the Gardens but are old, or in the Gardens but in low population numbers. Each species was sown in two duplicate trays.</p> One tray received no pretreatment and the other was subject to pretreatment. Pretreatments included cold stratification (subjecting seeds to low temperatures for a certain period), various methods of scarification (weakening or breaking a seed coat) and imbibition (soaking seeds in water). Beyond my project, I also engaged in other aspects of the Gardens’ propagation efforts and operations, including propagation by cuttings, seed collection and integrated pest management. Katy is extremely knowledgeable, passionate and hard-working and happily shared her expertise with me.</p> In addition to working on interesting projects, we interns were given the royal treatment. Every Monday afternoon a different member of the horticulture staff would lead a plant families class and plant walk, followed by a workshop exploring topics like herbarium collections, orchid mounting and even public speaking with CEO Brian Vogt. Every Friday we took field trips to various points of horticultural interest around Colorado and even as far as Wyoming. Different horticulturists and horticulture staff members would chaperone and provide expert-level information regarding the plant life and ecosystem of the area. It was a privilege to experience these incredible places with the people who know them best.</p> Among my favorite of the trips were Pawnee Buttes with Senior Curator & Director of Outreach Panayoti Kelaidis and Associate Director of Horticulture Dan Johnson; Loveland Pass and Betty Ford Alpine Gardens with Curator of Alpine Collections Mike Kintgen and Horticulturist Amy Schneider; and Mount Goliath, again with Amy.</p> Not only did we learn about native plants in the field and the dynamics of stewarding the Gardens, were also introduced to other potential opportunities in horticulture. We were given private tours from the horticulturists that grow plants for animal exhibits and landscaping at the Denver Zoo, wholesale production at Welby Gardens nursery and learned about invertebrate gardening within the conservatory of The Butterfly Pavilion.</p> I am astounded by the level of which the Gardens’ staff went out of their way to educate as well as entertain us. I cannot say enough good things about them. Genuine, welcoming, positive, passionate, kind, knowledgeable, supportive—the list goes on. They were the real reason why this experience has been so incredible. Oh, and I should mention I got paid! Hard to believe, I know.</p> It is sad to think that my time here is ending, but I am sincerely grateful to Denver Botanic Gardens, my mentor Katy and all those who make the Gardens the special place that it is. This internship was genuinely one of the best experiences of my life.</p> Dan Auerbach has always had an appreciation for science and nature, so he registered as a biology major when he enrolled at Temple University. By the end of freshman year, his strong interest in plants made him switch his major to horticulture. He’s extremely grateful for this internship opportunity, which will help him to pursue a horticulture career in Colorado, where he plans to move after graduation. </em></p>
Annual Flowers Curiosities of the Gardens</h3> August, during the "dog days" of summer, is the perfect time to view all the fantastic annuals at Denver Botanic Gardens. During this time, annual flowers are at their peak, revealing their mature height and showy blossoms. This walking tour highlights some of the more unusual annuals the Gardens has to offer. These plants’ strange and odd qualities rival any shockingly bright blossom of a traditional annual flower.</p> Begin your walking tour at the lowest point in the Sensory Garden. Near the tranquil water feature, you will see a living wall that is planted with an array of plant delights. In these wooly pockets that allow one to plant vertically, you will find a peculiar annual flower. This yellow button-shaped blossom has a red spot on the top giving it the common name of eyeball plant. </em>What’s curious about this plant, Acmella oleracea</em>, is when the flower or leaves are chewed, it causes numbness in the mouth, and a tingling sensation on the tongue. It is an herbal remedy to treat toothaches, giving it another common name, toothache plant.</p> Look just below the row of toothache plants and rest your eyes on a pink powder-puff shaped flower. Something unexpected happens when you touch the green compound leaves of sensitive plant, or Mimosa pudica. </em>Also known as touch-me-not, it becomes “alive” and closes its leaves over the stem. This almost extraterrestrial movement is an example of plant adaptation to protect itself from environmental harm or from predators.</p> Now walk westward and find yourself outside on the plaza of Marnie’s Pavilion. Continue to walk west and find the walkway lined with citrus trees. Here the West Terrace planters are adorned with an annual flower display of warm tones of orange, burgundy and russet. Here you will find a bizarre specimen plant with jagged, silvery-green leaves holding bright orange spikes decorated with purple flowers. This Madagascar native is called Solanum pyracanthum, </em>or devil’s thorn. Its freakish display of armor reveals in the language of plants that it is poisonous.</p> Towards the northwest end of the planter, you will find a trailing vine with small insignificant white flowers. Cardiospermum halicacabum, </em>or love-in-a-puff, holds a secret surprise inside its papery round lanterns. Inside are three, dark bean-like seeds with a white heart-shaped spot on the top. The genus name Cardiospermum </em>is derived from the Greek language meaning “heart shaped”.</p> Now turn to the east and double back to end your walking tour at the Science Pyramid. Flanking the main entrance on the east side are clusters of container plantings full of wild and avant-garde annual flowers. It’s easy to spot the dark purple, almost comical inflorescence of Amarnthus tricolor, </em>also known by its common name elephant head amaranth. The flower head resembles an elephant with a protruding trunk. This modern day fetish for fertility, phallic in form, is said to bring quick pregnancy to a bride if carried in her wedding bouquet. Juxtaposed to the towering elephant head amaranth is A. caudatus </em>‘Dreadlocks.’ The exceptional inflorescence of this amaranth is aptly named as its fuzzy pink dreadlocks cascade to the ground.</p> These are just a small sample of the remarkable and unfamiliar annuals planted at Denver Botanic Gardens. These more obscure varieties are just waiting to be discovered. Perhaps you’ve been inspired to create your own garden of curiosities for next season.</p>
The Chinese side of the mighty Himalayas, especially in Yunnan province, is considered a global hot spot for the world’s flora.</p> Yunnan comprises 152,124 square miles compared to Colorado’s 104,185 square miles. The flora of Yunnan is reputed to have more than 18,000 species of plants, while Colorado has just more than 3,000 species. Much of this dramatic contrast is due to Yunnan’s position straddling the Tropic of Cancer—along its border with Thailand and Burma, Yunnan has a tropical rainforest. And the many high peaks in the very north of Yunnan are clad with glaciers and have true alpine tundra. A tremendous range of ecosystems are found between these extremes, and the fantastic topography leads to a great many microclimates that form an archipelago of sky islands which have fostered endemism much like the Galapagos and its finches.</p> Certain genera seem to have gone off the deep end. There are literally hundreds of species of Rhododendron</em> found in Yunnan, and more than 100 kinds of Primula</em> (compared to Colorado’s modest four kinds!).</p> For those of us who love mountain flowers, Yunnan is idyllic. The Chinese have even appropriated the name “Shangri-la” (from a mythical town in the Western Himalayas in an old best seller) and applied it to Zhongdian—the mountain town at the heart of the Three Parallel Rivers National Park, where the Salween, the Yangtze and the Mekong flow through parallel channels separated by enormous alpine ridges of the Hengduan Mountains.</p> Here, numerous roads fan out, with many passes exceeding 15,000 feet in elevation. We were surprised that hiking at that elevation didn’t seem to cause the shortness of breath one experiences in the Colorado Rockies. One hike took us to nearly 16,000 feet! Since tree line can extend above 14,000 feet you have to get well above this to find the flowery alpine meadows. I was shocked to find quite large rhododendrons growing at elevations higher than any mountains in Colorado.</p> There were many genera I had never seen before here, especially Saussurea</em>—the “snow lotus” that are harvested by the ton in the high Yunnanese Mountains. These incredible composites look more like corals or perhaps extraterrestrials than any daisy you might imagine. We found several species on steep screes, just coming into their wild and wooly full bloom.</p> Primulas came in every color imaginable, from the deep pinks and yellows one expects to dark purples and luminous lavender Primula zambalensis</em>.</p> Another genus that quickly became a favorite was Rheum</em>, which includes the rhubarb of our gardens. There was a half dozen or more kinds in the mountains here, two with the flowers hidden by enormous colorful bracts. Rheum nobile</em> only grew on steep slopes, on loose scree where it produces its spectacular flower stalk and then dies. Superficially similar, Rheum alexandrae</em> forms wide mats in wet areas near alpine lakes and streams, with similar spikes of flowers.</p> The genus Corydalis is pretty special in Colorado, where our Corydalis caseana </em>ssp. brandegei</em> is likely the largest species in this enormous genus. In China, the corydalis may be much smaller, but unbelievably variable in leaf and flower color. Many grew on steep screes, often with piercing azure flowers or deep maroon foliage. There were many in bright yellow as well. “Corydalis” was almost a battle cry on the mountain when someone found a new one and called everyone else to come see it.</p> We were blessed with more than two weeks of sunny, clear weather, which is not typical in the monsoon season. One rainy day at lower altitudes brought out leeches, which latched on to a few of us who hadn’t used DEET—a rather bloody and unpleasant experience! I can guarantee you we shall use DEET on future trips in leech country!</p> Sorting through thousands of digital images taken during the trip is a mixed experience. It’s wonderful to revisit China on the one hand, but seeking out names in numerous books and on the web is a bit of a chore!</p> And no matter how many pictures one takes, in retrospect I wish I’d taken even more.</p>
