By Sandy Hollinsworth, Gilpin County Master Gardener
Increasingly, mountain gardeners and homeowners living above
8,000 feet are interested in landscaping with native plants to increase success
and promote sustainable, natural habitats. Native plants are inviting to
pollinators, birds, and mammals by providing food, shelter, and nesting
material. There are many benefits to using Colorado native plants including
biodiversity, beauty, adaptability, plus many are fire-wise plants. They are
naturally adapted to Colorado’s climates, soils, and environmental conditions. By
choosing native plants, gardeners can work with nature, rather than trying to
grow plants that are not suited to our local high-altitude conditions. Native
plants are also more resistant to pests and disease when grown in areas where
they are found in nature.
The mountain region is characterized by short growing
seasons, cool nights, strong sunlight, and high winds. The soils tend to be decomposed
granite, low in organic matter, and are usually very well-drained. Many native
plants prefer particular soil textures, whether sand or clay or loamy soils.
Almost all high mountain natives do not last as long in enriched garden soils;
they grow faster and may look fabulous for a few years then die sooner. Because
native plants are adapted to native soils they will thrive without fertilizer
or soil amendments. A small amount of compost may help work the rocky soil, but
gardeners will benefit by using compost sparingly. Species like columbines and
Jacobs ladder that grow in moist forests, may benefit from more compost but
otherwise, plant natives without fertilizer and other amendments.
Another consideration is microclimates, sections that are
hotter and drier, or cooler and wetter than the rest of the property. Every
garden and property have microclimates, depending on shade, sun, slope, water,
and wind protection. Grouping plants with similar sun, water, soil and
protection requirements will add to success and help with supplemental watering
as needed. Colorado mountain natives generally require less water unless they
naturally grow in riparian areas like Bluebells, Parry’s Primrose, Scouring-rush
Horsetail or Blue-Eyed Grass.
Maintenance in your garden may be easier with natives. It is
recommended not to rake away all dead leaves and twigs as it helps protect the soil
and offers protection to overwintering pollinators. In fall it is best not to cut
back plants but instead to leave seed-heads and dead stalks for food, perches
and winter homes for native bees, beneficial insects, and wintering songbirds. Wait
to cut back dead plant stalks in early spring at the first sign of green-up.
Mulch is critical for starting native plants from seed, and
it can be a huge help in establishing nursery-grown plants too. Gravel mulch is
best for retaining soil moisture without causing crown or root rot. Next best
is locally-sourced shredded bark mulch although it can blow away.
Non-native plants that are adapted to Colorado’s climate,
including CSU Plant Select species, may be more readily available. In years
with less than normal rainfall and snow these non-native plants may need supplemental
water, again pointing out the adaptive advantage of native species. Gardening
with native plants also prevents the introduction and spread of noxious weeds.
Many noxious weeds were intentionally introduced as garden plants and can crowd
out or change the garden’s native characteristics.
In Gilpin County, the following list of native plants are
found at 8,500 – 9,500’ on nature hikes and in established natural habitats.
Most are available at local native oriented nurseries or through CSU Extension native
plant sales. Inquire about sun and water recommendations to make sure to plant
the right plant in the right place. Seedlings will take a few years to fully
establish. Some reseed freely while others stay put and grow to their mature
spread and height over time. Wind, furry critters, birds, and domestic animals
may help spread seeds.
Pussytoes Antennaria
spp
Kinnikinnick Arctostaphylos
uva-ursi
Sulfur Buckwheat Eriogonum
umbellatum
Common Yarrow Achillea
millefolium (lantana)
Nodding Onion Allium
cernuum
Pearly Everlasting Anaphalis
margaritacea
Fringed Sage Artemisia
frigida |
Fringed Sage Artemisia frigida |
Rocky Mountain Columbine Aquilegia
caerulea
Blue Grama grass Bouteloua
gracilis
Harebell Campanula
rotundifolia
Indian Paintbrush Castilleja
spp.
Rocky Mountain Bee Plant Cleome
(Peritoma) serrulata
Showy Fleabane Erigeron
speciosus
Wallflower Erysimum
capitatum
Blanketflower Gaillardia
aristata
Richardson’s Geranium Geranium
richardsonii
Sticky Geranium Geranium
viscosissimum
Prairie Smoke Geum
triflorum
Sneezeweed Helenium Hymonoxys
hoopesii
Showy Goldeneye Heliomeris
(Viguera)
Scarlet Gilia Ipomopsis
aggregata
Rocky Mountain Iris Iris
missouriensis
Blue Flax Linum
lewisii
Silvery Lupine Lupinus
argenteus
Bee Balm/Horsemint Monarda
fistulosa
Showy Locoweed Oxytropis
lambertii
Rocky Mountain Penstemon Penstemon
strictus
Blue Mist Penstemon Penstemon
virens
Silky Phacelia Phacelia
sericea
Jacob’s Ladder Polemonium
viscosissimum
Pasque Flower Pulsatilla
(Anemone)
Black-eyed Susan Rudbeckia
hirta
Golden Banner Thermopsis
divaricarpa |
Current berries |
Wax Currant Ribes
cereum
Woods’ Rose Rosa
woodsii
Serviceberry Amelanchier
alnifolia
Chokecherry Prunus
virginiana
For more information about native shrubs https://extension.colostate.edu/topic-areas/yard-garden/native-shrubs-for-colorado-landscapes-7-422/
Almost this same list, plant photos, and some garden design
ideas are in this CSU Extension booklet:https://extension.colostate.edu/docs/pubs/native/MountainsSm.pdf