Whether you’re a Colorado native, a transplant from a humid climate, a
professional or novice gardener, making things grow along the Front Range is
challenging. Add a few years of drought conditions to the arid equation and that
challenge can become downright daunting. Armed, however, with some knowledge and
the right attitude, gardening in Colorado is a fun experience, says Dan Johnson,
curator of native plants for the Denver Botanic Gardens, who encourages
gardeners to take a carefree approach.
"There is always the chance that you’ll lose almost anything in your
garden. It’s experimental," says Dan, speaking to a drought-resistant
gardening class. But any inherent risk is worthwhile, as evidenced by the
23-acre Mecca at the Botanic Gardens, where classes are held.
What began for many gardeners as areas where hoses wouldn’t reach,
drought-tolerant planting now flourishes in high-profile areas and varies in
tone from quiet prairie to splashes of orange, blue, yellow, and red color. Dan
recommends touring Centennial Gardens, which feature native plants in a formal,
traditional way versus the naturalistic style commonly associated with
drought-tolerant approaches. It’s a five-acre garden located at 15th
and Little Raven Streets in Denver.
Specializing in native plants, a definition that encompasses plants from the
Front Range and southwest areas with similar climates, Dan enjoys testing local
soil with things like Salvia greggii and Texas rainbow cactus. Both
originate in Texas but thrive in Colorado gardens. The key word is test. Dan,
who has worked in the field for 15 years, unabashedly admits there is plenty he
does not know. "I’m still learning," he says with a grin when asked
about a random penstemon variety he does not recognize immediately or as he
points to a wayward bloom that’s outlasted its typical growing cycle.
His ongoing curiosity about the world of drought-tolerant plants is what
makes Johnson an ideal guide, though his knowledge is vast. Useful tips about
the compact but robust sunflowers (Helianthus pumilus) that come back
every year are gobbled up by the class, which comprises professionals, novices,
and one Colorado native. Names of native plants roll off Dan’s tongue when
asked questions about which plants thrive in high- altitude areas (suggestion:
Jamesia and Apache plume) or dry shady areas (suggestion: golden columbine).
Listening to Dan talk about his passion and profession makes the creation of
such beauty seem within grasp. Clad in a Denver Botanic Garden shirt, shorts,
and a ball cap he walks the gardens traipsing into patches of flowers and
shrubs, nodding at staff members, and answering a myriad of questions from
students and strollers.
Descriptions of the manzanita shrub that "doesn’t like its feet
wet" and "well-behaved" Blackfoot daisy are common from Dan who
likens native plants to persnickety children like an indulgent parent. Generous
with his time and knowledge, Dan shares anecdotes about a garden where he pulled
up a concrete driveway to reveal prickly poppy seeds that immediately began to
sprout. "The seeds had laid dormant for almost 50 years waiting for the
right conditions," he said. "They certainly earned the right to be
there."
Described as a gardening frontier for its ever-changing weather patterns and
clay-like soil, Colorado is a tough but rewarding place to plant, says Dan who
waits to see which varieties will "tough it out and survive".
Pointing to groupings of native grass, cacti, prairie sage, blue flax, and
penstemon, Dan describes gardens as tapestries created with seedlings and
plants. Grasses, says Dan, "tie it
all together in natural gardens, and are
beautiful in the fall and winter with different colors and textures."
Easily grown from seed, grass varieties like buffalo grass (Buchloe dactyloides)
stay short but can spread vigorously and gardeners with pets should be careful
about where they use foxtail barley (Hordeum jubatum) in their gardens
because of its sticky seeds and self-sowing habit. He suggests planting grasses
with blue flax and cutting it back in late spring to four to six inches. It
fills in quickly to lend a prairie-like atmosphere to the garden.
Knowing which plants spread, prefer shade or direct sun, and how much they
drink or like to be pruned is imperative to successful gardening. Snakeweed, for
example, becomes floppy with too much water. If kept dry the sub-shrub grows in
tight lime-green mounds with yellow flowers. California poppies, which Dan says
"can’t be beat for beautiful, drought-tolerant flowers," can be cut
to two inches in mid- summer after they’ve bloomed while Hesperaloe
parviflora, a yucca relative, continues to produce blooms along the same
stalk all summer long and also has winter interest, he says.
The class ran an hour over time in the gardens as Dan indulged students in
question after question. A handout with Latin and common names and planting
instructions for flowers, trees, shrubs, and grasses serves as a guide though
Dan admits it could be tripled and – by the end of the class – it is with
handwritten notes. Comments on the handout warn students about planting pitfalls
with generous offers from Johnson to provide seed if local nurseries cannot
furnish desired varieties.
After introductions, Dan narrates a slide show featuring drought-resistant
selections in different seasons and settings. It covers perennials, biennials,
annuals, and cactus, which Johnson says "have gotten a bad rap over the
years but when used as sculptural plants they offer something no other plant
adds." His favorites include the prickly pear (Opuntia) that
displays shocking pink flowers in the summer and claret cup (Echinocereus
triglochidiatus), which produces orange flowers in the spring. Dan suggests
using cactus with companion plants and shorter grasses such as the blue grama (Bouteloua
gracilis) and adds, "I will never have a garden without cactus."
After a five-minute break students amble out into the sunshine to ogle the
four areas that comprise the Denver Botanic Garden’s drought-resistant
gardens. Three native gardens known as the Western Panoramas include The
Ponderosa Border, Cottonwood Border, and Bristlecone Border. These complement
the somewhat wilder Dryland Mesa, Laura Smith Porter Plains Garden, and Gates
Montane Garden. The Wildflower Treasures also features native plants and is an
area that, as Johnson says, should not be missed.
The Laura Smith Porter Plains Garden, which was created in the early 1980s
has not been watered in five years and is burned every three to four years to
mimic natural conditions. But, as Dan says, the staff is limited. "We don’t
have any bison grazing here," he says with a chuckle.
When starting a garden with native plants, patience plays an important role,
Johnson says. Acknowledging that plant roots can become cramped in pots, which
hampers planting, Dan suggests buying deep nursery pots whenever possible, which
are easier to transition into gardens because they’ve already started a deeper
root system. Since drought-resistant plants are most often deep-rooted, roots
can wind themselves tightly around the inside of a pot and struggle to get
established in soil. Also, he says, allow plants – even those that are
struggling – to produce seed the first year because those seedlings often
survive better than the original nursery plant.
He also encourages people to expand their definitions of beauty when it comes
to native gardens. The shape and texture of a plant’s bark and the hue of its
leaves become factors when assessing groupings of native plants.
"It’s really the subtle things that make a garden beautiful," Dan
told the class. "Native gardens are often more about texture than flashy
color."
As students trail after Dan through the magnificent pockets of dry-land
gardens he murmurs about errant weeds and solicits volunteers. "If any of
you have free time come on down and help me weed. I’ll answer any questions
you have. Free rein," he says with a smile. Watching the faces of the other
students I wouldn’t be surprised if each and every one of them takes him up on
that offer.
