Denver Hellstrip Landscaping: Designing the Strip That Kills Everything

There's a strip of dirt between your sidewalk and the street. It bakes in July. It gets walked on, salted in winter, and ignored the rest of the year. It's too narrow to mow comfortably and too exposed to keep anything alive without a fight.

It has a name: the hellstrip. And we love designing them.

Most landscapers skip over it or throw in some sod and call it done. At Xeris, the hellstrip is one of our favorite spots on a property — because when it's done right, it transforms the entire curb appeal of the home and tells the street exactly who lives there.

Why It's Called a Hellstrip

The name isn't dramatic — it's accurate. The hellstrip sits between two heat-absorbing surfaces: the street on one side, the sidewalk on the other. In a Denver summer, that pavement radiates heat from both directions, pushing ground temperatures well above air temperature. It's the horticultural equivalent of a double oven.

Add to that: compacted soil from foot traffic, dog use, delivery trucks bumping the curb, and zero supplemental irrigation in most cases. The hellstrip gets whatever water nature provides — which in Denver averages about 14 inches per year — and nothing more.

Grass doesn't stand a chance. Not sustainably, anyway. You can keep it alive with enough water and effort, but you're fighting the environment every single day. The homeowners who get the most out of their hellstrip are the ones who stop fighting it and start designing with it.

Why Denver Hellstrips Are Uniquely Brutal

Denver's climate throws a specific combination of punches at the hellstrip that most parts of the country don't deal with simultaneously:

• High altitude UV — At 5,280 feet, UV radiation is significantly stronger than at sea level. Plants that look fine in a Seattle or Chicago hellstrip will bleach and burn in a Denver one.
• 300 days of sunshine — Denver's famous sunshine is great for solar panels. For unirrigated soil, it means accelerated evaporation and faster dry-down between rain events.
• Winter road salt and sand — City plows and de-icing crews treat the street, and that salt splash migrates into the hellstrip soil. Over years, it raises soil salinity and kills plants that would otherwise be perfectly hardy here.
• Hard freeze + rapid thaw cycles — Denver doesn't have a steady winter. We get polar vortex cold snaps followed by 65-degree days in January. That freeze-thaw cycle heaves roots and stresses shallow-planted material severely.
• Clay-heavy native soil — Denver's soil is predominantly compacted clay, which drains poorly, heaves in freeze-thaw, and bakes to near-concrete hardness in summer.

Any plant going into a Denver hellstrip has to survive all of this — not just one or two of these conditions. That narrows the list considerably. But the plants that do make it? They're beautiful, low-maintenance, and tough enough to last for years without attention.

What We Do Differently

The default hellstrip treatment in Denver is one of two things: dead grass or a flat layer of river rock with nothing growing. We don't do either.

Our approach starts with the soil. Before anything goes in, we amend the existing clay with compost and coarse grit to create drainage. Compacted clay that holds water in spring and cracks in summer is the silent killer of most hellstrip plantings. Fix the soil first, and the plants have a fighting chance.

From there, we design for three layers:

• Ground cover base — decomposed granite or crushed gravel as the primary surface. It reflects less heat than dark rock, suppresses weeds, and gives the design a clean, finished look between plants.
• Accent boulders — a few well-placed river rocks or fieldstone add visual weight, break up the linear strip, and protect plant crowns from foot traffic and mower drift.
• Adapted plant material — low-growing, deep-rooted natives and adapted perennials spaced to grow into each other over 2-3 seasons. We plant small and let them establish, rather than overcrowding at install and creating competition.

The result looks intentional — because it is. A hellstrip done right looks like a design decision, not an afterthought.

Plants That Actually Survive a Denver Hellstrip

This list isn't about what's pretty in a catalog. It's about what holds up in a south-facing, road-adjacent, Zone 5b strip that gets walked on and ignored. These are the plants we actually specify on hellstrip projects:

• Blue Grama Grass (Bouteloua gracilis) — Colorado's state grass. Drought-tolerant to an extreme, goes dormant in dry stretches rather than dying, and has that distinctive eyelash seedhead that looks great even in winter.
• Catmint (Nepeta faassenii) — One of our most-used hellstrip plants. Soft blue-purple bloom from late spring through fall, aromatic foliage that deer and dogs tend to avoid, and tough as nails once established. Stays under 18 inches.
• Prairie Zinnia (Zinnia grandiflora) — Tiny yellow flowers, spreading habit, virtually indestructible in Denver's summer heat. A Colorado native that thrives in the exact conditions that kill everything else.
• Russian Sage (Perovskia atriplicifolia) — Tall, airy, silver-blue, and bulletproof. Blooms all summer, handles road salt better than most, and adds vertical interest to narrow strips without getting too wide.
• Penstemon / Beardtongue (Penstemon strictus) — A Colorado native that puts on a show of purple-blue blooms in early summer, then drops back to a tight basal rosette that takes up almost no space. Pollinators love it.
• Agastache / Hummingbird Mint (Agastache rupestris) — Heat-loving, drought-tolerant, and covered in orange or purple blooms from July through frost. Hummingbirds and bees are on it constantly.
• Creeping Thyme (Thymus serpyllum) — For the edges and gaps between rocks. Handles foot traffic better than almost anything, stays under 3 inches, and blooms pink-purple in early summer.
• Low-growing Sedum (Sedum kamtschaticum, S. acre) — Succulent groundcover that stores water in its leaves, spreads slowly, and looks good year-round. Tolerates compacted soil and road salt splash better than most perennials.

What we don't plant in hellstrips: anything that needs regular watering to look good, anything over 36 inches tall (sight-line issues at street intersections), and anything with aggressive runners that will spread into the sidewalk cracks.

For a deeper look at the full plant palette we use across Denver xeriscape projects, see our guide to native plants for Denver xeriscape.

Know the Rules Before You Dig

The hellstrip is technically city right-of-way — you maintain it, but you don't own it. That means there are rules, and they vary by municipality.

City of Denver: Denver Water actively encourages hellstrip xeriscape and has rebate programs that apply to these strips. The city's primary restrictions are on height (generally keep plants under 36 inches for traffic visibility) and on hardscape (you typically can't pour concrete or install permanent structures in the right-of-way). Replacing grass with xeriscape in the hellstrip qualifies for Denver Water's Xeriscape Incentive Program rebates — often $1.50–$2.50 per square foot for turf removal.

Colorado law: Under C.R.S. § 38-33.3-106.4, HOAs cannot prohibit xeriscape or water-efficient landscaping. If your HOA has rules about the hellstrip, they can regulate aesthetics (plant height, materials) but they cannot require you to maintain live grass or prohibit drought-tolerant plants outright.

Lakewood and Jefferson County: Similar rules apply. Hellstrip xeriscape is permitted and encouraged. Check with your specific municipality if you're outside Denver city limits — rules on irrigation, plant height, and materials can vary slightly by city.

When we scope a hellstrip project, we check the applicable municipal code before the design goes to the client. No surprises after installation.

Hellstrip Design Inspiration

We keep a running board of hellstrip and roadway strip ideas that inform how we design these spaces — everything from plant combinations and rock placement to corner lot treatments and narrow linear strips. Take a look:

Follow @xerislandscaping on Pinterest for more design ideas.

If you want to talk through what would work on your specific strip — corner lot, narrow linear, or a challenging grade — reach out and we'll take a look. Hellstrips are one of our favorite problems to solve.

Ready to Fix Your Hellstrip?

We design and install hellstrip xeriscape across Denver and the Front Range. Tell us what you're working with and we'll put together an estimate.