Your site is an excellent candidate for a Colorado-native, dryland xeriscape, but the key is to design for Denver's combination of high solar intensity, 14-inch annual precipitation, winter cold, clay soil, and elevation rather than treating it like a conventional perennial garden. A 2,800-square-foot backyard can be divided into several ecological zones so that the plants needing the most attention are concentrated near the house and seating area, while the outer areas become increasingly self-sufficient. 1. Garden Assessment & Planning Recommended overall layout I would divide the yard approximately like this: Zone Approx. area Purpose Irrigation after establishment A — Arrival/house border 400 sq ft Highest visual impact Occasional B — Main xeric meadow 1,000 sq ft Native flowers + wildlife Minimal C — Seating retreat 350 sq ft Patio, seating, focal plants Occasional D — Water-feature zone 200 sq ft Small pond/basin + moisture-loving edge plants Low E — Cottonwood woodland 450 sq ft Shade garden Occasional F — Utility/wildlife edge 400 sq ft Native grasses/shrubs, habitat Minimal This creates a progression from cultivated → naturalistic → woodland, rather than making the entire yard look like one large planting bed. Microclimate map Your biggest environmental differences are likely to be: South/west Maximum afternoon radiation Hot reflected heat Rapid soil drying Higher evapotranspiration Best location for the most drought-adapted plants Central yard Full sun More moderate conditions Ideal for the main native perennial matrix North/cottonwood area Cooler Shaded Competition from cottonwood roots Potentially dry despite shade because mature trees consume substantial water Near structures Possible heat reflection Snow accumulation in winter Wind protection or wind tunnels depending on orientation Site assessment before planting For 2–3 weeks, make a simple map showing: 1. Sun at 9 a.m. 2. Sun at noon 3. Sun at 3 p.m. 4. Sun at 6 p.m. 5. Areas where rainwater naturally collects 6. Areas where snow accumulates 7. Wind exposure 8. Existing irrigation coverage 9. Cottonwood root concentration 10. Utility lines For soil, dig several holes approximately 12 inches deep. Record: Soil texture Depth before hitting roots/rock Drainage after filling the hole with water Compaction Earthworm activity Organic matter pH EC/salinity Most important: don't automatically amend the entire 2,800 sq ft with huge quantities of compost. Heavy clay can actually become problematic if amended incorrectly. --- 2. Design Concept & Plant Selection Design direction I'd use a Colorado High Plains / naturalistic xeriscape aesthetic: > Bold grasses + flowering native perennials + sculptural shrubs + strategically placed stone + restrained evergreen structure. Instead of dozens of unrelated plants, use repeated masses. A useful planting ratio is approximately: 40% ornamental/native grasses 35% flowering perennials 15% shrubs 5% evergreen/structural plants 5% special accents That will look much more sophisticated than a "collection garden." Core plant palette Structural shrubs Consider: Three-leaf sumac (Rhus trilobata) Mountain mahogany (Cercocarpus montanus) Rabbitbrush (Ericameria nauseosa) Wax currant (Ribes cereum) Woods' rose (Rosa woodsii) Serviceberry (Amelanchier alnifolia) where conditions permit These provide structure without requiring the irrigation associated with conventional ornamental shrubs. Flowering perennials Excellent candidates include: Blanket flower (Gaillardia aristata) Rocky Mountain penstemon (Penstemon strictus) Firecracker penstemon (Penstemon eatonii) Prairie zinnia (Zinnia grandiflora) Purple prairie clover (Dalea purpurea) Rocky Mountain bee plant (Cleome serrulata) Showy milkweed (Asclepias speciosa) Butterfly milkweed (Asclepias tuberosa) Harebell (Campanula rotundifolia) Prairie smoke (Geum triflorum) Lewis flax (Linum lewisii) Blanketflower Yarrow (Achillea millefolium) Grasses Grasses should be one of the major visual components. Look at: Blue grama (Bouteloua gracilis) Little bluestem (Schizachyrium scoparium) Prairie dropseed (Sporobolus heterolepis) Sideoats grama (Bouteloua curtipendula) Indian ricegrass (Achnatherum hymenoides) Blue grama + little bluestem would be particularly useful for establishing the visual language of the yard. Cottonwood shade zone Don't attempt to recreate a lush woodland under the tree. Instead consider: Wild ginger where appropriate and sufficiently moist Columbine species Richardson's geranium Western snowberry Oregon grape where conditions permit Native sedges Certain penstemons adapted to part shade Mulched open areas The cottonwood's roots are a major constraint. Do not create deep raised beds over its root zone or heavily disturb the soil. --- Planting combinations Rather than planting individual specimens randomly, create repeating communities. Combination 1 — Hot, dry south/west Blue grama + blanketflower + prairie zinnia + penstemon + rabbitbrush Visual effect: Fine grass texture Yellow/orange flowers Purple/blue flowers Late-season yellow Combination 2 — Main prairie Little bluestem + purple prairie clover + yarrow + milkweed + blanketflower This becomes your wildlife-oriented matrix. Combination 3 — Structural grouping Mountain mahogany + blue grama + penstemon + prairie smoke Excellent around seating areas or large boulders. Combination 4 — Late-season interest Rabbitbrush + little bluestem + blanketflower + asters This keeps the garden visually active when many spring perennials have finished. --- Four-season design Spring Focus on: Bulbs Prairie smoke Penstemon Early grasses Emerging foliage Summer Your peak flowering period: Penstemon Blanketflower Prairie clover Milkweed Yarrow Bee plant Fall This is particularly important in Denver. Use: Little bluestem Blue grama seed heads Rabbitbrush Late asters Golden foliage Persistent seedheads Winter Don't cut everything down. Leave: Grass seedheads Cone-like flower structures Shrub silhouettes Evergreen elements Stone features This gives you winter architecture and bird habitat. --- 3. Soil & Foundation Preparation Your compacted clay is probably the single biggest physical challenge. Soil strategy First obtain a professional soil test measuring: pH organic matter nitrogen phosphorus potassium soluble salts texture Colorado soils often have alkaline tendencies, but don't add sulfur merely because you assume the pH is high. For planting beds Rather than uniformly improving the whole property: Create individual planting zones. For new perennial beds: 1. Remove weeds. 2. Loosen compacted soil approximately 8–12 inches where feasible. 3. Incorporate a modest amount of mature compost. 4. Avoid creating a dramatically different "pot" of rich soil around each plant. 5. Finish with mulch. For drought-adapted plants, excessively rich soil isn't necessarily desirable. Avoid the classic clay-soil mistake Don't mix a small quantity of sand into clay. That can produce a concrete-like texture. If you need to improve the soil, organic matter + appropriate cultivation + plant selection is the safer strategy. --- Mulch Use approximately 2–3 inches of: shredded wood mulch arborist wood chips locally appropriate organic mulch Keep mulch several inches away from woody stems. In the most naturalistic prairie areas, you can eventually transition some areas toward lower-input mineral mulch or leave established grass/perennial matrices largely unmulched. --- Raised beds I would not use raised beds throughout the property. They're unnecessary for your native xeriscape and would increase cost and irrigation requirements. A raised vegetable bed could be added later if desired. --- 4. Complete Seasonal Planting Plan Because Denver's actual frost dates vary, use soil temperature and weather conditions, not a rigid calendar, for final planting decisions. Early spring Typical tasks: Soil test Remove invasive weeds Repair irrigation Mark planting zones Prune appropriately Divide suitable perennials Plant hardy bare-root/container plants when soil is workable Start seeds indoors for plants that benefit from it. Seed-starting principle Don't treat Colorado like the Midwest. High elevation means: intense sunlight short growing season cold nights rapid weather changes Harden transplants gradually. --- Late spring Once danger of severe frost has passed: Plant: Penstemons Milkweed Blanketflower Prairie clover Native grasses Shrubs This is also a good period for establishing the main irrigation system. --- Summer Your objective isn't continuous planting. It's establishment + succession + observation. First-year plants need considerably more irrigation than established xeric plants. Water deeply and less frequently rather than giving frequent shallow irrigation. Succession planting For annual wildlife color, consider: Rocky Mountain bee plant Native annual sunflowers Cosmos where appropriate Other locally adapted annuals But don't allow annuals to become the structural backbone of the garden. --- Fall Fall is extremely important for Colorado planting. Plant: Native perennials Hardy shrubs Grasses Spring-flowering bulbs Fall planting allows roots to establish while above-ground growth is slowing. Bulbs Use drought-compatible bulbs such as: Species tulips Crocus Alliums Camassia where site moisture allows Avoid designing a water-intensive spring bulb display. --- Winter Winter is primarily an observation and planning season. Don't automatically cut everything to ground level. Leave standing stems and grasses for: winter structure seed-eating birds overwintering insects snow capture Cut back selectively in late winter/early spring. --- 5. Water Management System This is where your xeriscape succeeds or fails. Your objective should not be "never water." The objective is: > Use irrigation strategically during establishment, then progressively reduce it as root systems mature. Recommended irrigation For most planted beds: Drip irrigation is the most appropriate starting point. Use separate irrigation zones for: 1. Shrubs 2. Perennials 3. Newly planted areas 4. Water-feature surroundings Don't put everything on one timer. Establishment schedule Year 1 Water deeply according to weather and plant establishment. New plants may need approximately: 2–3 watering events/week during hot periods initially progressively less frequent irrigation as roots establish The actual volume should be based on soil moisture rather than a fixed number of minutes. Year 2 Gradually reduce frequency. Encourage roots to explore deeper soil. Year 3+ Many appropriately selected plants should need only: occasional deep irrigation during prolonged drought supplemental water during extreme heat emergency watering for newly established/recently transplanted plants Some plants will still need periodic irrigation, particularly shrubs and plants placed in difficult microclimates. Don't promise yourself a completely irrigation-free landscape. Denver's 14-inch precipitation regime means supplemental water may remain valuable during extended drought. --- Water conservation system Use: 1. Hydrozoning Put plants with similar water requirements together. 2. Deep watering Encourage deeper roots. 3. Mulch Reduce evaporation. 4. Soil infiltration Improve the soil structure rather than simply watering more. 5. Rainwater capture Consider directing roof runoff toward appropriate landscape infiltration areas. However, don't concentrate large volumes of water against your home's foundation. 6. Rain barrel/cistern Useful for supplemental irrigation, but Colorado has specific rules governing rainwater collection. Check current Colorado and local requirements before installing a system. --- Small water feature Make it a recirculating feature, not a large ornamental pond. A good concept: stone-lined basin + small recirculating pump + shallow wildlife-accessible edge Keep it away from the cottonwood's main root zone. The feature can provide: visual movement birds insects sound a focal point But avoid creating a large high-evaporation pond that conflicts with your xeriscape objective. --- 6. Pest Control & Maintenance Your maintenance constraint is only 2 hours/week, so the landscape needs to be designed around that limitation. IPM system Use this sequence: Observe → identify → assess damage → tolerate minor damage → intervene only when necessary. Don't spray simply because you see an insect. Native plants will support a substantial insect community—and that's part of your wildlife goal. Common issues to watch Potential problems include: aphids spider mites grasshoppers caterpillars leafhoppers powdery mildew fungal problems after unusually wet periods rabbit/deer browsing depending on neighborhood wildlife First response Use: 1. Physical removal 2. Water spray 3. Pruning 4. Habitat management 5. Beneficial insects 6. Barriers 7. Targeted treatment only if necessary Avoid broad-spectrum insecticides whenever possible because they conflict directly with your wildlife objective. --- Fertilization Don't run a conventional high-fertilizer schedule. Your native xeriscape generally needs far less fertilizer than a traditional ornamental garden. First year Use soil-test results to determine whether nutrients are actually deficient. Compost should be your foundation rather than routine heavy nitrogen feeding. Established garden Usually: little or no routine fertilizer Overfertilization can encourage lush, weak growth and increase water demand. --- 12-Month Maintenance Calendar Month Main work January Review garden journal; inspect irrigation; plan next season February Seed planning; inspect trees/shrubs; order plants March Begin spring cleanup selectively; repair irrigation April Soil preparation; plant hardy perennials; weed control May Main planting; establish irrigation; mulch June Deep watering; weed control; pest monitoring July Irrigation adjustment; deadheading only where useful; wildlife monitoring August Deep watering during drought; collect observations September Major perennial/shrub planting window October Bulbs; mulch; irrigation winterization preparation November Clean up selectively; leave habitat standing December Minimal maintenance; review successes/failures --- Your 2-Hour Weekly Maintenance Routine Don't spend the two hours wandering around doing whatever looks urgent. Use a fixed system. 20 minutes — Inspection Walk the entire garden. Look for: wilting irrigation leaks weeds pest outbreaks broken stems animal damage 30 minutes — Water management Check actual soil moisture. Adjust irrigation according to: temperature precipitation plant establishment soil moisture 30 minutes — Weed control Pull weeds while they're small. 20 minutes — Pruning/deadheading Only perform tasks that improve plant health, appearance, or seed production. 20 minutes — Garden development Each week tackle one small improvement: adjust mulch reposition a plant repair edging improve a seating area clean water feature add habitat structure --- Budget Allocation — $4,500 I'd avoid spending the majority of your budget on plants. A reasonable first-year allocation would be: Category Target Native/adapted plants $1,600 Drip irrigation $650 Soil testing + amendments $450 Mulch/stone $500 Small water feature $500 Seating/paths/structural elements $450 Seeds/bulbs $150 Contingency $200 Total $4,500 The exact quantities will depend heavily on whether you install the hardscape yourself. --- The Most Important Design Rule Don't try to make 2,800 square feet of garden equally beautiful at the same time. Instead, create a visual hierarchy: House → beautiful intensively planted garden → seating/water feature → sweeping native meadow → cottonwood woodland edge. That gives you a destination. Your seating area becomes the "room," the water feature becomes its focal point, and the native planting flows outward from there. Suggested centerpiece Imagine a small natural-stone seating circle surrounded by: mountain mahogany + little bluestem + penstemon + blanketflower + prairie clover with a low recirculating water feature nearby. Beyond it, the planting becomes increasingly meadow-like: blue grama → little bluestem → milkweed → yarrow → blanketflower → rabbitbrush. Under the cottonwood, the aesthetic changes to a quieter woodland garden. That transition between sunny prairie and shaded woodland will make the relatively ordinary suburban backyard feel much more like a designed landscape. --- Your 3-Year Establishment Strategy Year 1 — Build Goal: establish infrastructure and root systems. Priorities: Soil testing Irrigation Paths/seating Water feature Main shrubs 60–70% of perennial planting Mulch Weed control Expect to water substantially more than you ultimately will. Year 2 — Establish Goal: reduce dependency. Fill planting gaps Increase plant density Reduce irrigation frequency Allow grasses to expand Refine combinations Begin replacing plants that clearly dislike their microclimate Year 3 — Naturalize Goal: transition toward the low-maintenance landscape you actually want. Reduce irrigation further Allow self-seeding where desirable Stop unnecessary fertilization Reduce pruning Maintain mulch Divide/reposition only when necessary Let the strongest plants dominate At that point, the garden should increasingly look as though it belongs in Colorado rather than being a Midwest garden transplanted to Denver. --- One important Denver-specific step Before purchasing large quantities of plants, I'd verify the exact species against Colorado State University Extension / Denver-area native-plant resources, because "native to Colorado" doesn't automatically mean "appropriate for a dry, exposed Denver 5,400-foot site." Some natives prefer foothill woodland, riparian conditions, or higher-moisture soils. The most useful next step would be to turn this into an **actual 2,800-sq-ft planting map**: I can lay out the six zones, approximate plant quantities and spacing, a plant-by-plant shopping list, irrigation zones, water-feature/seating placement, and a **$4,500 first-year purchasing plan**.