Best plants for Denver gardens
Denver gardens sit a mile high in USDA zone 6a on alkaline clay, with only 12 to 15 inches of precipitation, intense high-altitude sun, and a last frost in mid-May. The defining challenges are heat and drought, frequent hail, and an active emerald ash borer infestation, so the plants below are water-wise, hail-resilient, and ash-free.
Last updated 2026-05-31
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Not sure what to plant? The finder matches Front Range trees, shrubs, perennials, and groundcover to your soil, water, sun, and zone.
Denver growing conditions
- USDA hardiness zone
- 6a (warmer 6b urban-core pockets, cooler 5b at the edges)
- Elevation
- 5,280 ft
- Avg. annual precipitation
- ~12 to 15 in
- Soil
- alkaline clay loam, high pH, often expansive (swelling), low organic matter
- Avg. last spring frost
- mid-May
- Avg. first fall frost
- early-to-mid October
- Growing season
- ~150 days
At exactly a mile high, Denver's urban heat island nudges the core toward zone 6b while exposed edges stay 5b. The combination of high altitude and ~300 sunny days makes sun far more intense than in most of the country, and the alkaline, often-expansive clay locks up iron (causing chlorosis) and heaves foundations. Amend heavily and water deeply.
What's challenging in Denver
Emerald ash borer is in Denver
EAB was confirmed in Denver in 2025; the city has roughly 330,000 ash trees, about one in six of all its trees. If you have an ash (genus Fraxinus), consult a certified arborist about treatment versus replacement, and don't plant new ash. The trees below are diverse, non-ash species. (source)
Mile-high heat, low water, 2026 drought
Denver receives only 12 to 15 inches of precipitation a year, and in 2026 Denver Water declared its first Stage 1 drought since 2013. Outdoor watering is limited to two days a week, never between 10 a.m. and 6 p.m. Low-water, deep-rooted plants thrive; thirsty bluegrass struggles. (source)
Hail Alley
The Front Range sees the most large hail in North America, with peak storms May to August. Tough, flexible, fast-recovering plants fare best.
Top trees for Denver
Ranked for Denver's hail, drying wind and low water use.
One-seed JuniperJuniperus monosperma10 to 20 ftlow waterColorado nativeUSDA 3 to 8
Rocky Mountain Juniper (species)Juniperus scopulorum15 to 30 ftlow waterColorado nativeUSDA 3 to 8
Arizona CypressHesperocyparis arizonica30 to 50 ftlow waterUSDA 7 to 10- Arizona Cypress 'Blue Ice'Hesperocyparis arizonica20 to 30 ftlow waterUSDA 7 to 10
Singleleaf Pinyon PinePinus monophylla15 to 30 ftlow waterUSDA 3 to 7
'Vanderwolf's Pyramid' PinePinus flexilis25 to 30 ftlow to medium waterColorado nativeUSDA 4 to 7
Thornless Common Honeylocust (IMPERIAL®)Gleditsia triacanthos40 to 50 ftlow to medium waterUSDA 3 to 9- Thornless Common Honeylocust (NORTHERN ACCLAIM®)Gleditsia triacanthos30 to 45 ftlow to medium waterUSDA 3 to 9
Top shrubs for Denver
Ranked for Denver's hail, drying wind and low water use.
Apache plumeFallugia paradoxa4 to 6 ftlow waterColorado nativeUSDA 4 to 9
Big sagebrushArtemisia tridentata3 to 8 ftlow waterColorado nativeUSDA 3 to 9
Cliff fendlerbushFendlera rupicola3 to 6 ftlow waterColorado nativeUSDA 5 to 8
CliffrosePurshia mexicana4 to 8 ftlow waterColorado nativeUSDA 4 to 8
Common juniperJuniperus communis2 to 4 ftlow waterColorado nativeUSDA 2 to 7
Curlleaf mountain mahoganyCercocarpus ledifolius10 to 20 ftlow waterColorado nativeUSDA 3 to 8
Dwarf wild indigoAmorpha nana1 to 2 ftlow waterColorado nativeUSDA 4 to 9
FernbushChamaebatiaria millefolium4 to 6 ftlow waterColorado nativeUSDA 4 to 8
Top perennials for Denver
Ranked for Denver's hail, drying wind and low water use.
Bee Balm/HorsemintMonarda fistulosa24 inlow waterColorado nativeUSDA 3 to 9
Bigelow's TansyasterMachaeranthera bigelovii24 to 48 inlow waterColorado nativeUSDA 4 to 8
Black-eyed SusanRudbeckia hirta24 inlow waterColorado nativeUSDA 3 to 9
BlanketflowerGaillardia aristata12 inlow waterColorado nativeUSDA 3 to 10
Blue FlaxLinum lewisii18 inlow waterColorado nativeUSDA 4 to 9
Blue Mist PenstemonPenstemon virens12 inlow waterColorado nativeUSDA 3 to 8
Bush SunflowerHelianthus pumilus20 inlow waterColorado nativeUSDA 4 to 9
Butterfly MilkweedAsclepias tuberosa18 inlow waterColorado nativeUSDA 3 to 9
Top groundcover for Denver
Ranked for Denver's hail, drying wind and low water use.
Blue grama grassBouteloua gracilis8 to 18 inlow waterColorado nativeUSDA 3 to 10
Buffalo grassBouteloua dactyloides4 to 8 inlow waterColorado nativeUSDA 3 to 10
Mat penstemonPenstemon caespitosus2 to 4 inlow waterColorado nativeUSDA 3 to 8
Small-leaf pussytoesAntennaria parvifolia2 to 5 inlow waterColorado nativeUSDA 3 to 8
Sulfur buckwheatEriogonum umbellatum6 to 12 inlow waterColorado nativeUSDA 4 to 8
DOG TUFF™ grassCynodon 'PWIN04S'4 to 6 inlow water
Fire Spinner ice plantDelosperma 'Fire Spinner'1 to 2 inlow waterUSDA 5 to 10
Hens and chicksSempervivum tectorum2 to 6 inlow waterUSDA 3 to 8
Rebates & water rules in Denver
Denver Water residential customers. Resource Central is sold out of Garden In A Box for 2026; new kits come back next spring, and its interest list is the way to hear when ordering opens.
Denver Water customers. All 2026 discounts are allocated; Denver Water says it will post an update if discounts return, and Resource Central says its 2027 applications open in spring.
Watering rules: Summer Watering Rules run May 1 to Oct 1; under the 2026 Stage 1 drought, watering is 2 days/week, never 10 a.m. to 6 p.m. (days assigned by address). current rules →
What's open right now across the Front Range, with dates and the rules that trip people up: lawn replacement rebates by city →
Statewide: new Colorado turf rules (SB24-005/HB25-1113) limit nonfunctional turf in new development, and HOAs can't ban xeriscaping (SB23-178). Read the statewide rules →
Local resources near Denver
- Botanic garden
Denver Botanic Gardens, World-class gardens including the Denver Water Water-Smart xeriscape demonstration garden. - Extension
CSU Extension, Denver County Master Gardeners, Master Gardener help plus demonstration gardens (incl. Harvard Gulch Park). - Reference
Denver Public Library, Garden & Xeriscape resources, Free local gardening and xeriscape guides.
When to plant in Denver
Plant in spring (April to May) or early fall, amend the clay with compost, and water deeply but infrequently. Expect hail May to August. Hold tender annuals until mid-May. Denver's mile-high sun is intense. Mulch beds and let them warm before tomatoes go out.
Video
Video PlantTalk Colorado: xeriscape & planting videos (CSU Extension + Denver Botanic Gardens)
Denver gardening FAQ
- What hardiness zone is Denver?
- Denver is USDA zone 6a, with warmer 6b pockets in the dense urban core and cooler 5b at exposed edges.
- When is the last frost in Denver?
- The average last spring frost is mid-May; wait for warm soil before planting tender annuals.
- Should I plant an ash tree in Denver?
- No, emerald ash borer is established in Denver. Plant a diverse non-ash species and consult a certified arborist about any existing ash.
- Is there a turf rebate in Denver?
- Denver Water offers up to $750 off turf removal through Resource Central, but every 2026 discount is already allocated. Resource Central says 2027 applications open in spring; watch Denver Water's page for whether it funds another round.
Targeted guides for Denver
Plan your garden
Not sure what to plant? The finder matches Front Range trees, shrubs, perennials, and groundcover to your soil, water, sun, and zone.
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