Flowering vs. Non-Flowering Plants for Colorado Yards

Flowering plants make seeds inside a flower and a fruit; non-flowering plants make seeds in cones (the conifers) or spores (ferns, mosses, horsetails). On a Front Range lot that distinction decides what survives: the flowering shrubs and perennials give a yard its color from Mother's Day to the first October frost, and the non-flowering evergreens hold the yard together through the other seven months, shrug off hail, and screen the neighbor in January.

This guide sorts the two groups for Colorado homeowners, lists the plants that survive USDA zone 5b clay, hail and drought, explains Denver Water's watering rules and Colorado's HOA landscaping law, and ends with what a seller does to the yard in the 30 days before listing.

Flowering plants: what they are and which ones work in Colorado

Flowering plants (angiosperms) are the largest plant group on earth, and they include far more than the obvious. Every grass is a flowering plant with a small wind-pollinated flower, so blue grama, Colorado's state grass, sits in this group next to the lilac. Every fruit tree, every perennial, every vegetable and every deciduous shade tree along the Front Range is an angiosperm. The Rocky Mountain columbine, the state flower, is one.

What matters at 5,280 feet is which of them hold up. The Plant Select program, run by Colorado State University and Denver Botanic Gardens, tests plants for exactly this climate, and the list below is drawn from what survives a Front Range yard with three waterings a week:

• Perennials for sun and clay: Rocky Mountain penstemon, blanket flower, blue flax, chocolate flower, purple coneflower, yarrow, catmint, Russian sage, sedum and hardy ice plant. All bloom from June through September on drip alone once established.
• Native shrubs: Apache plume, rabbitbrush, fernbush, three-leaf sumac, serviceberry and chokecherry. Serviceberry gives white flowers in April, fruit in July and red leaves in October on 10 gallons of water a week.
• Flowering trees that survive hail and a dry August: hawthorn, Kentucky coffeetree, bur oak, honeylocust and flowering crabapples like these, which bloom in late April along the Front Range and take the 40-degree temperature swings of a Denver spring without cracking.
• Grasses: blue grama and buffalograss lawns use one-third the water of Kentucky bluegrass; little bluestem and switchgrass hold a slope and stand through snow.

Cut flowers are the one flowering-plant category that does not come from a Colorado yard in winter. A vase on the kitchen island for an open house, or a bouquet sent to a buyer relocating from the Bay Area, comes from a service such as San Francisco flower delivery. The plants above stay in the ground.

Non-flowering plants: conifers, ferns and what they do for a Colorado yard

Non-flowering plants reproduce without a flower. Conifers (gymnosperms) carry seeds in cones; ferns, mosses and horsetails release spores. Ginkgo, a gymnosperm that grows well in Denver's parks, is a non-flowering tree even though it drops leaves like a maple. In a Front Range landscape the conifers do the year-round work:

• Colorado blue spruce, the state tree, 40 to 60 feet at maturity; give it 20 feet from the house and 15 gallons a week for the first three summers.
• Ponderosa pine and pinyon pine: the two most drought-proof trees on the Front Range once established. Pinyon stays under 20 feet.
• Rocky Mountain juniper and upright junipers: the screening plant for a lot line, no supplemental water after year two.
• Mugo pine and dwarf spruce: foundation plants that hold their shape under a roof-slide of snow.
• Ferns and mosses: north-side shade only, with steady water. Denver's 15 inches of rain a year and 10% winter humidity make them a small, high-water corner, not a yard.

The hail rule separates the groups. A June storm shreds hostas, hydrangeas and broad-leaf annuals in four minutes. Conifers, fine-leaf natives, ornamental grasses and sedums come through with no damage, which is why every Plant Select yard leans on them.

Flowering vs. non-flowering plants in a Front Range yard

The Front Range growing zone and planting calendar

Denver, Aurora, Littleton, Lakewood and Fort Collins sit in USDA hardiness zone 5b to 6a; Colorado Springs, Castle Rock and Parker in 5a to 5b; Evergreen and Conifer in 4b. The last spring frost lands around Mother's Day and the first fall frost in early October, which leaves 20 weeks. Plant trees and shrubs in April or in September, when the soil is warm and the sun is not; plant perennials after the last frost; and water every new tree through its first three winters on any week without snow cover. Our seasonal gardening in Denver calendar lists the month-by-month tasks.

Denver Water rules and what a lawn costs to run

Denver Water's summer watering rules run from spring through October 1: water no more than three days a week, never between 10 a.m. and 6 p.m., and not during rain or high wind. Aurora Water, Castle Rock Water, Parker Water and Sanitation and the northern Colorado providers set their own schedules on the same pattern. A quarter-acre Kentucky bluegrass lot in Parker or Aurora costs $900 to $1,800 a summer in water at 2026 tiered rates; the same lot in blue grama and drip-fed natives costs a third of that. The Denver utility providers and costs guide lists who bills water in each suburb and what the tiers look like.

Turf-replacement rebates exist in most of the metro. Denver Water, Aurora Water and Castle Rock Water each fund lawn-to-xeriscape conversions through Resource Central or their own programs, and the state's turf replacement program adds money through the Colorado Water Conservation Board. A conversion runs $8 to $20 per square foot installed (plants, drip, mulch and rock), and the rebate covers part of it. Our Front Range xeriscaping guide walks through the design and the rebate paperwork.

What your Colorado HOA is allowed to say about your landscaping

Colorado Revised Statutes 38-33.3-106.5 bars an HOA from prohibiting xeriscape, drought-tolerant plants or vegetable gardens, and since 2021 from prohibiting artificial turf in a backyard. The HOA is allowed to set design standards: plant a percentage of the front yard in living material, keep it maintained, submit a plan to the architectural committee first. HRCA in Highlands Ranch and most Douglas County HOAs run a 30-day review. Separately, Colorado's 2024 turf law stops new nonfunctional grass on HOA common areas and commercial sites starting in 2026, which is why so many Front Range entry monuments are turning to native grass. Read the Denver HOA rules and fees guide before you pull the sod.

Plants to avoid on the Front Range

• Aspen below 7,000 feet. It suckers into the lawn, gets canker and borers in Denver heat, and lives 15 years. It belongs in Evergreen, not Englewood.
• Ash trees. Emerald ash borer, confirmed in Boulder County and in Denver metro cities including Arvada, Westminster, Broomfield and Littleton, kills untreated ash in 3 to 5 years. Treat a mature ash ($150 to $400 every two years) or budget $1,000 to $3,000 to remove it. A dying ash in the listing photo costs more than either.
• Russian olive, Siberian elm and tamarisk. Colorado lists them as noxious or nuisance species; the county can require removal.
• Anything that needs daily water: hydrangeas, azaleas, impatiens. They die in the first hot week of July under a three-day schedule.

Landscaping before you list: the 30-day curb appeal plan

Front Range buyers judge a home from the driveway, and REcolorado showing data puts the outside photo first in every feed. Landscaping done in the month before listing returns more per dollar than any interior project short of paint; the preparing and adding value before selling page ranks it against the rest.

1. Remove the dead. Every dead branch, hail-shredded shrub and brown sod patch. Sod patches run $2 to $3 per square foot installed.
2. Mulch and edge. Two inches of shredded wood mulch on every bed, a clean spade edge at the lawn. $300 to $800 on a typical lot.
3. Add flowering color in the front, in containers if it is winter: pansies in March, geraniums and petunias from Mother's Day, mums in September.
4. Keep the evergreens tidy. Prune junipers off the walkway and lift the spruce skirt 12 inches off the ground so the house reads bigger.
5. Run the sprinklers for showings, then winterize. If the listing runs into October, blow out the system before the first hard freeze and leave the invoice for the buyer; see the Colorado sprinkler blowout and backflow preventer guide.
6. Photograph at 10 a.m. Front Range light at noon flattens every bed.

For the rest of the exterior list, read Denver curb appeal tips from a local and the post on 6 low-maintenance plants for Denver gardens. Buyers who want the yard already done search the xeriscaped homes for sale in the Denver metro.

Where to go next

• Preparing and adding value before selling
• Denver utility providers and costs guide
• Xeriscaping your Colorado home: a Front Range guide
• Spring lawn care in Colorado
• Meet the Kenna Real Estate Group agents
• Search every home for sale in Colorado

Talk to the Kenna Real Estate Group

The Kenna Real Estate Group at Keller Williams DTC walks the yard with you before listing, tells you which of the six steps above your street rewards, and photographs the home when the light is right. Call or text 303-955-4220. A live person answers. Not a robot, not a phone tree. To see how the competing yards look, search every home for sale in Colorado.