Scabious – late summer green roof plant

Sep 28, 2019

Scabious may sound un attractive but they are a beautiful group of plants. Furthermore the species tend to flower late in the summer.

Scabious in rough grrass, Greenwich London

Scabious in rough grass

Three species of Scabious

We have three native ones here in the UK – Small, Field and Devil’s bit.  Small is the one for green roofs, though Field may grow in roofs with deeper substrates. Devil’s bit tends to like soils that are moister than on green roofs.

The plants get their name from its herbal remedy of relieving ‘the itch’ or scabies. How effective this was who knows, but we do know that the plants are very attractive to pollinators. Flowering from  July to September, butterflies, moths and bees flock to its nectar. It is also the main larval foodplant of the Marsh Fritillary butterfly, a threatened species in the UK and Europe.

Recent encounters with Scabiosa

We have had a few couple of recent encounters with the species away from green roofs. Stumbling across a stand in Greenwich, London, I shall be going back to collect the seeds. The disused building plot will soon be no more. I shall take the seeds and spread on a green roof somewhere in London.

Scabiosa - green roofs

Hover fly on Scabiosa triandra

I recently visited the south of France to see our French guide gang. Scabiosa triandra, although not found in the UK, is very common in southern Europe. And it is perfect for a Mediterranean green roof. I found it growing at Le Crau, which must be one of the driest parts of France! It was everywhere. In the fields where the famous white horses graze it was one of the main flowers. Like Small Scabious, in both places, it was a magnet for pollinators.

Adding to your green roof

Scabious can be added to your green roof, either as a plug or from seed. Native seeds are available commercially. You can also collect wild seeds. Scabious plants produce thousands of seeds. So only take a few seed heads leaving plenty to maintain the local population.

Within the guide itself, there is a comprehensive guide to planting options for green roofs.