Plants for a purpose: Plants for rooftop gardens

A windy situation can dry out soil very quickly so it’s best to either choose plants that can cope with dry soil or install a simple irrigation system.

Wind can also shred leaves and blow the petals off flowers so avoid plants with large, wide leaves like ornamental bananas and flowers with delicate petals like oriental poppies.

Good choices are plants like yarrow which have strong stems, small flower clusters and flower for weeks on end.  They are available in a wide range of colours.

This variety produces flowers of different shades of orange-red throughout the summer months which turn creamy-yellow as they age. If you cut back the stems after the first flush of flowering, you may be rewarded with a repeat show of flowers later in the season.

• Flowers in summer
• Fully hardy
• Grows to 60cm tall
• Moist but well-drained or well-drained soil
• Full sun

• Exposed

Buddlejas do well in windy situations and, if space is limited, there are a range of more compact varieties available.

This compact plant is a great choice for a container and produces masses of pinky-red flowers from midsummer. To keep the plant at roughly the same height cut back all the stems hard in March and you’ll be amazed how quickly it grows back come the early summer!

• Flowers in summer
• Hardy
• Grows to 2m tall
• Well-drained soil
• Full sun
• Exposed or sheltered

It’s good to include some evergreen plants for year-round interest. Lavender will cope with an exposed situation as long as it has good drainage. There are also evergreen grasses and sedges that will enhance the look of a container over winter.

Next is an easy to grow evergreen plant that looks like an ornamental grass. It has lovely, arching, orange-green, narrow leaves that will add a warm glow to containers during the winter months.

• Evergreen foliage
• Hardy
• Grows to 50cm tall
• Moist but well-drained or well-drained soil
• Full sun or partial shade
• Exposed or sheltered

This plant produces masses of small daisy flowers which start off white and then turn pink as they age. It will flower from spring right the way through to autumn and sometimes into winter. Just ensure it’s planted into a container where the soil or peat-free compost is free draining. Then, all you need to do is trim back, which is best done in the autumn.

• Flowers in summer
• Hardy
• Grows to 1m tall
• Well-drained soil
• Full sun
• Exposed

It can be a challenge to find flowering plants for a shady situation, but the good news is that there are ways of creating a rooftop garden in the shade with year round interest.

There are several evergreen shrubs that don’t mind growing in the shade such as Pittosporum. By choosing easy to grow types, like Euonymus, with white markings on the leaves, these will lighten up the space.

This is a tough shrub that can be easily shaped if needed that will cope with shade and even drought once established. The leaves have creamy-white edges that develop a pink tinge as they age and will produce clusters of small green flowers in early summer.

• Semi-evergreen foliage and flowers in spring
• Fully hardy
• Grows to 1m tall
• Well-drained soil
• Full sun or partial shade
• Exposed

Introducing contrasting foliage shape into a planting scheme adds extra interest and there are several choices for a shady area. The strap like leaves of Pheasant-tail grass and various varieties of Carex work well. If you like a flowering strap leaf plant, lilyturf is an excellent choice for a shady spot with both purple and white flowering varieties.

As the name suggests this plant produces pure white flowers from late summer all the way into early winter. It’s easy to look after with narrow evergreen leaves and its white flowers will lighten up the darkest spot.

• Flowers in autumn
• Hardy through most of the UK
• Grows to 60cm tall
• Moist but well-drained soil
• Full shade
• Sheltered

If you’re looking for low growing, matt-forming, evergreen ground cover for a shady rooftop spot, the white flowered form of Bugle plant would be a good choice.

This low growing plant will quickly form a mass of bright green, oval shaped leaves in the darkest of situations as well as spikes of purple flowers late spring early summer. Not only can you enjoy the flowers, but pollinators will be sure to pay them a visit too.

• Flowers in spring
• Fully hardy
• Grows to 15cm tall
• Moist but well-drained soil
• Full sun or partial shade
• Exposed or sheltered