Is My Parking Lot Green?
In this article, we discover how green parking lot design can reduce flooding, improve shade, and create healthier landscapes for offices, schools, and neighborhoods.
For most people, parking lots are just places to park quickly, juggling groceries or searching for a spot at busy locations. But for those who design landscapes, parking lots are more than vacant slabs of asphalt; they can be environments that cause or solve problems with little attention.
Traditional parking lots create environmental problems: they trap heat, pollute stormwater, and make landscapes unwelcoming. The good news is that it doesn’t have to be this way.
A well-designed green parking lot can absorb stormwater rather than shed it, cool ambient temperatures, support wildlife, and even make a property more appealing. In other words, the most ignored part of many sites can become one of the hardest-working parts of the landscape or even a feature. So, how can you start transforming a neglected parking lot into a thriving green space?
Let’s dig into five approaches that can turn a lifeless parking lot into a healthier, intelligent landscape. Each highlights a powerful way to rethink what a parking lot can be.
What Is a Green Parking Lot?
A Simple Idea with Big Environmental Benefits
A green parking lot isn’t some futuristic concept cooked up by a group of nutty/crunchy environmental scientists. It’s simply a parking area designed to work with nature rather than fight it.
Traditional parking lots are designed to move water as fast as possible into storm drains. A green parking lot slows the water down, filters it through living soil and plants, and allows much of it to soak back into the ground.
This approach reduces erosion and flooding, protects nearby streams, and improves the overall health of the landscape.
Why Suburban Properties Benefit the Most
Suburban properties stand to gain the most from green parking lot design. Think about the places where you see endless seas of pavement: shopping centers, churches, office parks, schools, and community centers. These sites often have acres of parking lots that sit half-empty most of the time, baking in the sun and shedding stormwater.
With the right conditions, a shopping center lot in July can have pavement temperatures over 140 degrees. That’s stifling heat.
Add shade trees, permeable surfaces, and rain gardens, and suddenly that same intensely hot parking lot becomes cooler, greener, and far more pleasant for everyone who uses it. This brings us to the specific strategies that make it possible.
1. Permeable Pavement That Lets Water Soak In
How Permeable Pavement Works
Permeable pavement might sound more high-tech than it really is, but the concept is surprisingly simple.
Instead of creating a hard, solid surface that water can’t penetrate, permeable pavement allows rainwater to pass through small pores. The water then flows into a stone base underneath, where it slowly percolates into the soil.
Common types include:
• Permeable pavers
• Porous asphalt
• Pervious concrete
All these surfaces let water soak into the ground rather than run off to storm drains and creeks.
Why It’s a Gamechanger for Stormwater
Stormwater runoff is one of the biggest environmental problems in developed landscapes. Every time rain hits pavement, it becomes polluted; it collects dust, oil, fertilizers, tire residue, and other pollutants as it flows past. That nasty, and sometimes toxic, cocktail then flows into streams and rivers.
Permeable pavement helps filter that water through soil and stone before it reaches groundwater or nearby waterways.
Where It Works Best
Permeable pavement works especially well in:
• Overflow parking areas
• Residential developments
• Smaller commercial parking lots
• Pedestrian plazas
Permeable pavers are a serious investment for a property, but the environmental payback is exponential.
2. Rain Gardens That Turn Runoff Into a Resource
Capturing Water from Most Parking Lots' Waste
A rain garden is a shallow landscaped basin designed to capture and absorb runoff. Instead of directing water into pipes and off-site, the runoff flows into a planted basin where it can slowly infiltrate into the soil. This process filters pollutants and helps recharge groundwater, turning rainwater from a waste product into an asset.
Rain gardens are often placed in low spots at the edges of parking lots or at the ends of parking rows where water naturally collects. While they may look like ordinary planting beds, they actively reduce local flooding, filter pollutants, and improve the site’s ecological health, all while supporting attractive landscaping.
Plants That Thrive in Rain Gardens
The key to a successful rain garden is choosing plants that tolerate both wet feet for a short time and drought conditions. They are known as riparian plants.
Some reliable performers include:
• Beebalm (Monarda didyma)
• Blue Flag Iris (Iris versicolor)
• Joe-Pye Weed (Eutrochium purpureum)
• Black-eyed Susan (Rudbeckia hirta)
• Cardinal Flower (Lobelia cardinalis)
Native plants are usually the best choice because they’re adapted to local conditions and support pollinators.
The Visual Upgrade Parking Lots Desperately Need
Let’s be honest. Most parking lots are eyesores. They’re big, flat, monotonous, boring rows of asphalt with the occasional struggling shrub or a weak tree tossed in for decoration.
Rain gardens break that monotony. They add texture, seasonal color, and a bit of life to spaces that would otherwise feel harsh and sterile.
I’ve had property owners tell me their rain gardens became the most attractive part of their entire site and an unexpected feature. Beyond aesthetics, rain gardens can also lower irrigation costs, attract pollinators, and add long-term value to properties. That’s saying something when the starting point was a parking lot.
3. Shade Trees That Transform the Entire Experience
Cooling the Asphalt Jungle
Trees are the unsung champions of green parking lot design. A mature shade tree can reduce pavement temperatures by 30 degrees or more in the summertime.
Heat is brutal on asphalt. Shade helps extend the life of the pavement while making the site far more pleasant for visitors.
Tree Placement That Actually Works
Planting trees in parking lots sounds simple, but many designs end up as failures. The biggest mistake is giving trees tiny planting pits that aren’t large enough to support the root mass of a healthy tree. Trees planted this way struggle, just barely hanging on for years, or die in the first summer after planting.
To have healthy parking lot trees, they need a generous soil volume and good drainage. Larger planting islands or connected soil trenches allow roots to spread and support long-term growth. Even better is when planting areas are large enough to plant small groves of trees.
The Hidden Economic Benefits
There’s also a financial argument for planting more trees.
Studies show shaded lots reduce pavement maintenance costs and improve customer comfort, attracting more visitors on hot days.
4. Bioswales That Quietly Manage Stormwater
Nature’s Drainage System
A bioswale is fundamentally a landscaped channel designed to move and filter stormwater runoff.
Instead of squeezing water into underground pipes, bioswales slow the flow down and allow soil and plants to remove sediment and pollutants. They function similarly to a rain garden. When used, they are one of the most effective stormwater tools available in landscape design.
Why They Outperform Traditional Storm Drains
Traditional storm drains are designed to move water away from a site as fast as possible. The problem is that this approach increases erosion and flooding, and it carries pollutants directly into waterways.
Bioswales take the opposite approach. They slow the water down and give it time to filter through the soil.
Designing Bioswales That Look Like Landscapes
One of the biggest misconceptions about bioswales is that they look like drainage ditches full of weeds. They don’t have to.
With thoughtful design, bioswales can look like naturalistic planting beds filled with color and seasonal interest provided by grasses, perennials, and small shrubs. In fact, some of the most striking landscapes I’ve seen were quietly doubling as stormwater infrastructure.
5. Vegetated Parking Islands That Bring Life to Asphalt
Why Every Parking Row Needs a Landscape Break
Parking islands are the landscaped areas between rows of parking spaces.
They serve several purposes:
• Break up large expanses of pavement
• Provide space for trees
• Capture and absorb stormwater
• Improve the visual character of the site
Without them, parking lots are giant baking sheets, not meant for humans.
Plants That Survive Tough Parking Lot Conditions
Parking lots are not easy places for plants to thrive. They deal with heat, reflected sunlight, compacted soil, mechanical damage from cars, and occasional winter salt exposure.
You’ll need to check your local conditions, but some top performers include:
• Hackberry
• Willow Oak
• Red maple cultivars
• Serviceberry
• Ornamental grasses
• Groundcover roses
Selecting resilient plants supports the long-term success of parking lot landscaping.
Designing Islands That Actually Protect Trees
One design move is allowing water from the pavement to drain into planting islands. This approach feeds trees with natural rainfall rather than sending that water straight into storm drains, but you also need to make sure the tree pit drains.
I’ve seen trees thrive on parking lot runoff. It turns out that a little stormwater can be a valuable resource when managed properly. That’s gallons of free water being applied to trees that they normally wouldn’t receive.
Smart Design Principles That Make Green Parking Lots Work
Soil Volume Matters More Than You Think
Healthy landscapes start underground. Trees and plants need enough soil to support their root systems. It isn’t possible to get a grand, broad canopy from a tree that’s planted in a four-foot by four-foot pit. When planting areas are too small, plants struggle no matter how much attention and care they receive.
Providing generous soil volume is one of the best investments a designer can make.
Native Plants Are the Real MVPs
Native plants are the pillars of sustainable landscapes. They tolerate local weather conditions, support wildlife, and require less maintenance once established.
In stormwater landscapes, especially, native grasses and perennials perform like champs.
Maintenance Keeps the System Healthy
Even the most intelligent design needs maintenance. Rain gardens need regular watering during the establishment period. Bioswales may require sediment removal. Trees benefit from proper pruning and care.
Fortunately, most green parking lot landscapes require no more maintenance than traditional landscaping, and often less once plants mature and cover more area.
The Future of Parking Lot Design
For the good of our communities, parking lots are evolving. Cities and communities are recognizing that these giant-sized paved areas can play an important role in managing stormwater and reducing urban heat.
Instead of being environmental problems, parking lots can become part of the solution. Landscape architects around the Country are increasingly designing parking areas that function like small ecosystems. Water is routinely captured, filtered, and reused. Trees provide shade, food, and habitat for wildlife.
It’s a far cry from the harsh asphalt fields we’ve grown used to.
Conclusion: Turning the Most Ignored Space into an Asset
Parking lots are easily the most overlooked landscapes in our built environment. They’re often designed as an afterthought. Basically, most meet the requirement for a certain number of parking stalls and the leftover space between the building and the property line.
Typically, they are large, hot, and visually uninspiring tracts of land. But with a little creativity and smart design, they can become some of the most productive landscapes on a property.
And here’s the awesome part. Once you start looking at parking lots through this lens, you can’t see it any other way. Good, green parking lot design will be the norm in that world.
