Green roofs aren’t just a beautiful way to add greenery to urban environments—they’re also incredibly practical. From improving insulation and reducing energy costs to helping manage stormwater runoff and improving air quality, green roofs offer a lot of benefits. But one of the most important decisions you’ll make when planning a green roof is choosing the right plants.

In this guide, we’ll explore the best green roof plants, talk about what makes a plant suitable for rooftop life, and offer suggestions for different types of green roof environments. Whether you’re working with a small residential roof or a large commercial installation, the plants you choose will make all the difference.

What Makes a Plant Ideal for a Green Roof?

Not all plants are cut out for life on a rooftop. Conditions up there are tough—intense sun, high winds, limited soil depth, and extreme temperature fluctuations. The best green roof plants are those that are hardy, drought-tolerant, low-maintenance, and capable of thriving in shallow soil. Here are some traits to look for:

• Drought tolerance
  Green roofs often have limited water retention, especially extensive systems with shallow soil. Plants need to survive long dry spells without constant irrigation.
• Low nutrient needs
  Soil on green roofs is typically lightweight and doesn’t offer the same richness as garden soil. Plants must be able to grow well without heavy feeding.
• Shallow root systems
  Roots shouldn’t dig too deep—especially for roofs with thin layers of growing medium. Shallow-rooted plants are safer for the roof structure.
• Cold and heat resistance
  Roofs can become very hot in the summer and bitterly cold in the winter. Plants need to handle both extremes without wilting or dying off.
• Low maintenance
  Once established, the ideal plants should be able to survive with minimal care, avoiding the need for constant attention or pruning.

Top Plant Types for Green Roofs

Choosing the right category of plant is the first step. While individual species matter, knowing what types of plants work best for green roofs will help guide your planning.

• Succulents
  These are the classic green roof choice, especially for extensive roofs. Succulents like sedum store water in their leaves, making them highly drought-tolerant. They also tend to grow low to the ground, which helps in windy conditions.
• Grasses and grass-like plants
  Certain ornamental grasses or grass-like perennials can add visual texture and are quite resilient. Many also go dormant in harsh conditions and bounce back later.
• Herbs
  Some herbs, like thyme and chives, do well on green roofs and offer a bonus—they smell great and can even be harvested occasionally.
• Wildflowers
  If you want a more naturalistic look or are aiming to support pollinators, native wildflowers are a good choice. They can create a meadow-like effect that changes with the seasons.
• Groundcovers
  Low-growing plants that spread easily are great for covering the soil and protecting it from erosion and sun exposure.

Best Plants for Different Green Roof Systems

There are two main types of green roofs—extensive and intensive—and plant suitability depends heavily on which kind you have.

Extensive Green Roofs

These roofs are thin, lightweight, and designed for low maintenance. The soil is shallow, usually less than six inches deep, so plants need to be extremely hardy and drought-resistant.

Great options for extensive green roofs include:

• Sedum (stonecrop)
  This is the gold standard. There are many varieties, all of which are tough, colorful, and spread well. Sedum can handle hot, dry, windy conditions like a champ.
• Delosperma (ice plant)
  Another drought-tolerant succulent that comes in vibrant colors and can withstand poor soil and heat.
• Sempervivum (hens and chicks)
  These rosette-forming succulents are perfect for shallow soil and require almost no care.
• Thymus serpyllum (creeping thyme)
  A low-growing herb with small purple flowers, it’s drought-tolerant and smells pleasant.
• Festuca glauca (blue fescue)
  A compact ornamental grass that adds color contrast with its silvery-blue foliage.

Intensive Green Roofs

These are more like traditional rooftop gardens. They use deeper soil, sometimes more than a foot deep, and can support a wider range of plants, including small trees and shrubs.

For intensive green roofs, consider:

• Lavandula (lavender)
  Thrives in full sun and well-drained soil, and adds fragrance and color to your green roof.
• Echinacea (coneflower)
  Attracts pollinators and handles both drought and cold very well.
• Rudbeckia (black-eyed Susan)
  Bright yellow blooms that hold up well in rooftop conditions and require minimal care once established.
• Panicum virgatum (switchgrass)
  A tall, native ornamental grass that adds height and movement to your roof space.
• Salvia
  Long-blooming and loved by bees, many salvia species handle heat and drought easily.

Table: Green Roof Plant Selection by Condition

FAQs About Green Roof Plants

What’s the easiest plant to grow on a green roof?
Sedum is the easiest and most common plant for green roofs. It’s low maintenance, survives in harsh weather, and spreads quickly.

Can I grow vegetables on a green roof?
It depends on the roof. Intensive green roofs with deeper soil and irrigation systems can support vegetables. Extensive green roofs usually can’t handle the root depth or water needs of most veggies.

Do I need to water green roof plants?
For extensive green roofs, irrigation may only be necessary during establishment or extreme drought. Intensive systems might need regular watering, depending on the plants used.

Are green roof plants evergreen?
Some, like certain sedum and hens and chicks, are evergreen or semi-evergreen. Others may die back in winter but regrow in spring.

Can I use native plants on a green roof?
Absolutely. In fact, native plants are often ideal because they’re adapted to your local climate and usually require less maintenance.

How do I maintain plants on a green roof?
Initial maintenance includes watering until plants are established, weeding, and occasionally replanting. After that, maintenance is minimal, especially for extensive systems.

Conclusion

Choosing the best green roof plants means thinking about your specific roof type, climate, and the kind of maintenance you’re willing to do. Succulents like sedum are great all-rounders for shallow, sun-soaked rooftops. For deeper soil systems, you can enjoy a wider palette that includes ornamental grasses, wildflowers, herbs, and even small shrubs.

A thoughtfully planted green roof doesn’t just add curb appeal—it helps regulate temperature, supports wildlife, and turns an unused surface into a productive green space. Take the time to choose resilient, low-maintenance plants, and your green roof will reward you with years of beauty and benefits.