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>
