You may be surprised to learn that many species of plants produce flowers in March, from bulbs to the lesser-known variety of perennials, shrubs and ornamental trees that offer fragrance and color in the garden. Let us explore the Gardens to learn about what’s in bloom despite the cool temperatures this time of year!</p> Cercocarpus intricatus</a></em></h3> Native to Colorado and the Intermountain West, the little leaf mountain mahogany is a drought tolerant, native evergreen that blooms late March through most of April. This shrubby, slow grower is in the family Rosaceae and is not a true mahogany (family Meliaceae). In a natural setting, wildlife will forage this plant, which can encourage new growth and a fuller habit. Look for it on the north side of the Roads Water-Smart Garden</strong>.</p> Tulipa humilis </em>‘Lilliput’</a></h3> When it comes to spring bulbs, tulip species (versus Dutch-bred hybrids) aren’t one of the "usual suspects" in the garden. Native to Turkey and the Caucasus, blooming at the end of March and into early April, this cultivar is hardy to zone 3. As you walk west along the Roads Water-Smart Garden</strong>, look for red blooms and foliage low to the ground on the south bed adjacent to the pathway planted among lamb’s ear (Stachys byzantina</em>).</p> Galanthus nivalis</em> ‘Flore Pleno’</a></h3> (Double) snowdrop is one of the earliest bulbs to flower. Expect flowers to emerge as early as February and into March. The cultivar 'Flore Pleno' is called double snowdrops as it produces dainty, nodding double flowers. Snowdrops provide an important source of food for honeybees when few other plants are flowering. Galanthus</em> does well under trees and naturalize by producing offsets. It is a great drought and shade tolerant early bloomer that is cold hardy to zone 3. As you near the end of Shady Lane</strong> look south to see this bulb in bloom.</p> Arctostaphylos</em> × coloradensis </em>‘Panchito’</a></h3> Stop by the Darlene Radichel Plant Select® Garden</strong> and you will find a broadleaf evergreen commonly called manzanita. It produces lovely pink small heather-like flowers which hang in small clusters from the branches. Flowers last for up to six weeks and may produce tiny apple-like berries in the summer that songbirds and small mammals enjoy eating. This plant provides shelter and cover for wildlife while leaf litter provides habitat for insects and pollinators. ;</p> Chaenomeles japonica</em></a></h3> Flowering Japanese quince is a traditional garden plant which has long been enjoyed for its open, arching habit and spring flowering bright red, pink, orange or white blooms, depending on cultivar. Flowers emerge in late March and early April and are typically 1- 2 inches with bright yellow stamens. See if you can spot all seven specimens as you walk through the Japanese Garden</strong>.</p> Prunus tomentosa</a></em></h3> The cherry blossoms in Washington, D.C. and throughout Japan are a worldwide known phenomenon. Did you know we have the same experience at Denver Botanic Gardens? A classic flowering ornamental, Nanking cherry has profuse fragrant pale pink blooms that you cannot miss. Note the habit and the form of the plant, which can be pruned to highlight arching habit. Enjoy several other Prunus</em> species in bloom as you stroll through the Japanese Garden</strong>. </p> Pulsatilla vulgaris</em></a></h3> Hairy flower stems emerge from the ground in spring and simultaneously purple flowers bloom as foliage begins to emerge and form. This plant, also known as Pasque flower, spreads by seed and will naturalize throughout the garden. There are many specimens to see as you stroll through the Rock Alpine Garden</strong>.</p>
The City Nature Challenge</a> is a yearly community science event for folks in cities all over the world to observe and document biodiversity in their own backyards, and 2025 was the 10-year anniversary. To participate, people make observations of any organism – plant, animal, insect and more – on iNaturalist</a> for a few days in late April to early May. This is followed by a short identification phase – where a community of naturalists work on identifying all species observed. The biodiversity data crowd-sourced through iNaturalist contributes important information to scientists and land managers. </p> In the Denver-Boulder metro area, more than 9,714 observations were submitted by 764 people of 1,260 species! We nearly doubled our number of observations and observers compared to 2024, and we broke our previous record in 2020 of ~7,000. This year, our most observed species was Chokecherry (Prunus virginiana</em>). Fun species observed included a silver fox</a>, long-eared owl</a>, Abert’s squirrel</a>, bobcat</a>, prairie violet</a>, beaver</a>, black-crowned night heron</a>, little brown bat</a>, American mink</a>, elk</a>, moose</a>, Northern Harrier</a> and black bear</a>. We even had 145 research-grade observations of 26 species</a> that are listed as rare, endangered, or threatened by NatureServe or the U.S. Fish and Wildlife Service (over twice as many as last year). </p> For 2025’s global challenge, there were 3.3 million observations of almost 74,000 species made by 103,000 people from over 62 countries around the world. This brings the total number of observations made during the past 10 years to almost 13 million! The leading city for numbers of observations, species, and observers was La Paz, Bolivia. </p> Thank you to everyone who participated in this year’s City Nature Challenge. We are looking forward to participating with you next year.</p> Shout out to the winners of the Denver-Boulder City Nature Challenge:</strong>Most observations: @Phyllisholst with 405 observations of 150 speciesMost identifications: @Andershastings with 2,265 observations </p>
Why water your garden in the winter?</h4> Colorado winters can vary dramatically when it comes to snowfall and precipitation totals. In the Mile High City and its surrounding suburban communities, any snow accumulation lasting longer than a few days is rare and drought conditions are the norm. Because of this, urban gardens can often suffer from winter drought conditions causing long term challenges especially for newly planted trees and shrubs. </p> Although many perennial plants shed their leaves and go into dormancy during winter months, they are still very much alive and their root systems, buds and stems continue to grow. When there is insufficient moisture, this stresses the plant and inhibits essential metabolic processes from occurring properly. Examples of this include winter kill in lawns and perennial plants not reemerging in spring as the ground thaws. Drought stress can also be seen in trees and shrubs for several years after the drought occurs since it can affect growth rate, leaf production and overall vigor. Drought stress can also make plants more susceptible to disease and insect damage. </p> Best methods for winter watering:</h4> Winter watering should be done 1-2 times per month from late fall into early spring and should be conducted on warm days when temperatures are above 40 degrees Fahrenheit and the soil is thawed. It should be done using a hose and watering wand or attachable sprinkler around midday allowing enough time for the water to infiltrate the soil before freezing. Placing several empty cups in the garden and watering until each cup has accumulated half an inch to one inch of moisture will ensure that you have adequately watered the soil around the roots of your plants. Using a deep root waterer is also a great way to water trees and shrubs. Once finished, hoses should be removed from the faucet spigot and stored to prevent freeze damage to water pipes, hoses and watering wand attachments. </p> What plants in the garden need to be watered in winter?</h4> Plants that should be watered through the winter months include deciduous and evergreen trees, shrubs and groundcovers as well as perennial flowering plants. Newly planted trees and shrubs are the most crucial as this supplemental watering will allow them to establish more quickly and help them reach their maximum potential growth the following spring and summer. Evergreens are prone to winter desiccation, a process in which more water is lost through the foliage than is absorbed through the roots of the plant, resulting in yellowing or browning of the foliage. It is not necessary to water xeric plants such as cacti, succulents and many drought tolerant native plants as consistently throughout the winter as these plants are well suited for experiencing long periods of drought without detrimental long-term effects.</p>
