Five Ferns Thriving in City Walls

The ferns gracing our garden walls provide a reminder of the tenacity of nature but did you know that there are many out there to be discovered?

Our wild plants have an incredible way of making a home in unlikely places. If you are looking for a sign of nature’s resilience, look no further than the delicate ferns gracing garden walls across the North East. Defying the odds, these little wonders find sanctuary in the nooks and crannies of man-made structures. Below, explore five species that have not only adapted but thrived in this unique habitat. Together, they provide a reminder of the beauty that lies in unexpected places, even in the hearts of our towns and cities.

Maidenhair Spleenwort

As its name suggests, Maidenhair Spleenwort is known for its graceful and delicate appearance. Adorning the cracks and crevices of walls, this fern features glossy black stems and small fan-shaped fronds displayed in opposite pairs. Its ability to survive in inhospitable conditions is truly remarkable and it is perhaps the fern you are most likely to spot on walls and buildings across our region.

Did you know that there are infact three subspecies of Maidenhair Spleenwort in our region, each with it’s own distinct habitat. The sort you’re most likely to see in urban areas is subspecies quadrivalens which is able to grow well in mortar.


With its intricately lobed leaves, Wall-rue is another eye-catching fern that has made a home on our walls and structures. It has club-shaped leaflets that appear in groups of three, easily setting it apart from other common ferns. This fern displays a fascinating ability to grow vertically, seemingly defying gravity and its feathery foliage brings a touch of elegance to whichever stone or brick surface it inhabits.

Black Spleenwort

Among the ferns that have found a home on the North East’s walls, Black Spleenwort stands out with its unique beauty. This fern features dark, glossy fronds with characteristic toothed margins. Despite its delicate appearance, the Black Spleenwort is remarkably hardy and can withstand harsh conditions. If you spot distinctive, triangular fronts with purple-black stalks, you likely have this rather lovely species.


It is difficult not to be captivated by the distinctive appearance of the Hart’s-tongue. With its elongated, undulating fronds, this fern stands out amongst its peers. The glossy green fronds of this species are singular, not divided like other ferns. Underneath, you’ll likely spot distinctive orange spores. The plants you spot in walls and stonework are usually smaller than their woodland cousins but still make for quite the sight against a background of cold, grey stone.

Hart’s-tongue gets its name from its long, tapering leaves which are said to resemble the tongue of a deer. The leaves are certainly tounge-shaped and even have pointed, curly tips.


Rustyback is a fascinating and scarce species sometimes found on walls in our region. Its unique characteristics include fronds covered in rusty-colored scales, giving it its distinct and memorable name. These scales are thought to provide protection against moisture loss and help reflect sunlight, allowing the fern to tolerate dry and sunny environments, including barren garden walls! Rustyback is rare in the North East but can be in limestone habitats and mortared walls in select corners of our region.

The ferns which grace our walls serve as a powerful reminder of the adaptability of nature. Why not look beyond the obvious on your next city walk and discover beauty in unexpected places? If you spot any of these, we’d love to hear from you on social media!

James Common
NHSN Senior Naturalist

James is a local naturalist passionate about plants. He works as NHSN’s Senior Naturalist and elsewhere, volunteers as a botanical Vice-County Recorder and verifier for the UK Ladybird Survey. He keeps a blog at Common by Nature.