A living roof is known by many synonyms: you might know them as “green roofs” or “eco-roofs” instead. Although they’re not a new idea, there’s been a huge push recently to add more nature back into urban settings and cities around the world. Fortunately, there are tons of green roof plants to choose from.
Check out my 15 top picks for the best plants to cultivate on your living roof, no matter where you live.
Why You Need a Living Roof
Rooftop gardens are becoming more popular than traditional roofing options several reasons. For example, layering plants along the top of your home helps to keep it cool in the heat of summer. Similarly, doing so adds an extra layer of insulation during cold winters. In addition, you can select fragrant plants to attract wildlife such as hummingbirds, bees, or butterflies. They’ll also keep your home smelling wonderful.
Living roofs help the environment while reducing the negative impacts of development. As a result, this comes with some pretty awesome perks for homeowners. Expect your green roof to:
- Lower energy consumption
- Reduce urban heat island effect
- Provide stormwater management
- Reduce runoff and boost water quality
- Lower noise and air pollution
- Allow space for urban gardening
- Produce fresh oxygen and shade
- Improve your home’s return on investment
- Boost your roof’s lifespan
- Appear more aesthetically pleasing and healthy.
Plus, numerous green roof companies exist to help you transition while you install your green roof but the process is so affordable you could DIY. Start small, using the roof of a shed for practice first before making permanent changes to your home. You could convert the roof of a gazebo, doghouse, or even a birdhouse to incorporate an eco-friendly living roof.
What Type of Living Roof is Right For You?
A living roof requires hardy plants that can survive a wide array of conditions most plants find unsuitable. Because they’re positioned on an unmoving rooftop, the plants are vulnerable to the elements. Excellent options will even look attractive and offer shelter or food for the surrounding wildlife. The best plants for a green or living roof must be:
- Poor soil-tolerant
The right green roof plants for your project will depend on where you live. Roof plants need to withstand heat, cold, and rain. As a result, the best plant options are those that tend to grow naturally in inhospitable areas like mountains, cliffs, or deserts. The plants you have available to you will depend on your planting zone, but they’ll inevitably fall into a few main categories:
- Aromatic Herbs: These plants grow low and spread out, making them perfect for a living roof. They often grow naturally in a rocky, dry location.
- Grasses: Few grass options can withstand a living roof’s conditions without daily watering, but they’re great for covering huge areas. Not to be confused with lawn grass, these plants tend to sprout pink and purple flowers during summertime. Some grow naturally in dunes or ocean cliffs, making them a great choice for homes near the water.
- Succulents: A perfect option for the bulk of green roof plants, as they thrive with little water and soil. Plus, there are tons of colors and options to choose from.
- Wildflowers: Although these grow better in deeper soil than the others on this list, they can provide an excellent design accent and be used to attract pollinators like butterflies.
15 Best Green Roof Plants
With your local weather conditions in mind, you can choose the right plants that will last years to come. Here are 15 of the best options:
Aster alpinus is a plant from the Alpine region. It’s hardy in intense weather and thin soil conditions, making it perfect for your green roof. The purple blooms pop up in brilliant displays, and they attract butterflies in large hordes.
Sedums are awesome for creating your own living roof for a number of reasons. They cover the ground well, and are easily maintained. These hardy plants grow on their own in a shallow amount of substrate, which means there’s not much-added weight on your home. Furthermore, their stunning yellow blooms attract honeybees.
White Stonecrop is also another type of hardy succulent sedum. It offers mat-like stems and a mass of leaves with star-shaped flowers during the summer. The plants do well in a thin layer of dry soil, and they’re very low maintenance. If you enjoy sedum roofs, as they grow low to the ground and covers the entire roof area well, you can take advantage of added insulation from the plants as well.
Like other sedums on this list, Widow’s Cross thrives in conditions where most plants die. It’s hardy, drought-resistant, and a favorite choice for green roofs. The pink and green flowers are attractive and wildlife-friendly. Expect them to bloom in the spring and summer months.
Meadow Saxifrage (Saxifraga granulata) erupts in snow-white blooms between April and June, and the kidney-shaped leaves offer a stunning display for a green roof. The plants grow up to 50 cm tall, offering volume to your home. Plant this option in a full-sun location with well-draining soil, as it’s a grassland plant, and expect the pollen and nectar to attract bees.
Sedum spurium, also known as two-row stonecrop, is a tough plant perfect for ground cover. It’s another sedum roof option, but this one requires poor, well-draining soil. The star-shaped flowers are red and pink from late summer to fall and the leaves can retain water. This means it can keep your home safer from fire than grass roofs. Bumblebees love this plant as well.
A low-lying plant that’s commonly planted in lawns, Birdsfoot Trefoil is a member of the pea family. It offers yellow blooms during summer that transform into seedpods later into the season. They’re ideal for a green roof and rich in pollen to attract butterflies and bees.
Houseleeks, also known as as Sempervivums, are hardy succulents commonly planted in containers indoors. In addition, they make awesome green roof plants. They’re evergreen, alpine species that can grow on anything—even rocks or bricks—all year long. Their highly attractive foliage spirals out in an eye-catching way and the flowers bloom throughout summer. There are many varieties to choose from, but most gardeners select the cobweb species for a living roof.
Yarrow offers clumps of pink or white blooms that are sweet-smelling and attractive to wildlife. It’s great for a living roof and is an edible plant with many medicinal properties. Wildflowers like yarrow must have no less than 100 mm of growing medium to support the plants, however, so you may need to bear in mind the added weight of a yarrow roof. You’ll also need to water these plants regularly, especially during dry spells.
Perfect for a green roof because it adapts well to harsh conditions, sea thrift is a grass-like plant commonly found on the coast. It prefers sandy soil and dry conditions, and the plants produce long stems of white or pink flowers throughout the summer.
Blue sedge (Carex flacca or Carex glauca) is a grass that’s ideal for a roof due to its hardiness. It’s an ornamental plant that survives in many types of soil and climates. The grass grows in clusters shaped like balls, and the leaves offer a stunning blue hue, allowing it to stand out around other low-maintenance plants.
Another edible plant for a living roof, oregano (Origanum vulgare) is a Mediterranean herb that requires little maintenance. It thrives in well-draining soil, and when planted on a roof, can create a huge herb garden with excellent ground cover. The flowers are rich in pollen, and butterflies adore the plants.
Standard garden thyme (Thymus vulgaris) is another edible herb you can plant along your green roof. It tends to grow in a dry, rocky location like its native Mediterranean basin, and the plants grow to a few inches tall with purple and pink flowers in the early summer months. The best part about this plant is that, like yarrow, it’s so hardy you can even walk across it.
You can also use Thymus serpyllum, or “Minimus” thyme, which grows a bit taller when mature and provides excellent groundcover. It looks great alongside standard thyme for a contrast in color, height, and variety. The pink flowers bloom in early summer and the care required is the same.
An excellent option for an extensive green roof in a wet location, moss is a lightweight and low-maintenance plant. It just needs a little soil, shade, and plenty of moisture to survive. As a result, it’s a common choice for a living roof because it can survive extreme temperatures as well. If you’re going the DIY route, moss can quickly grow across your roof and begin to thrive in as little as 2-4 months.
Mondo grass is also known as Ophiopogon japonicus. It’s shaped like grass, but is a Japanese flowering plant from the Asparagaceae family and comes in a variety of colors. The leaves reach around 10 cm tall, and the plant can grow in partly sunny or full-sun locations. Expect the plants to grow slowly while you’re getting them established, but since they’re evergreen, they’ll offer roof color all year long. Keep the soil moist to wet for the best results.
Issues with a Living Roof
Before you build your own green roof, consider the issues you may encounter with a garden on top of your house. The plants you select, which depends on your home and the climate, can mean the difference between a thriving garden and not.
Drought and waterlogging are common issues you can face if you don’t have the right plants for your climate, so you may need to combat this issue by offering sustainable drainage during heavy rainfalls to keep the plants healthy.
Unfortunately, living roofs also aren’t as affordable as a traditional roof over a long period of time, and they require a lot of attention. You’ll need to maintain the plants and make sure the area you offer them is right for their needs. Watering regularly is likely.
Finally, if your home doesn’t have the structure to handle an increasing weight, a green roof may not be ideal. After all, green roofs aren’t for everyone. They’re heavier than traditional roofs and may require you to retrofit the home so you can increase the load.
While flat roofs can often handle the added capacity, pointed roofs don’t make great options for supporting plant life.