Take a closer look at ten of the fascinating wildflowers you could encounter on garden walls across Gosforth’s Wild Web. How many can you find?
Did you know that our garden walls are a fantastic place to encounter a variety of colourful and often unusual plants? With their excellent drainage and ability to retain the sun’s warmth, walls create a unique habitat that attracts a wide range of native and naturalised plants. Even the mortar used in wall construction plays a role, enticing several lime-loving plants rarely seen elsewhere in urban environments. With summer in the air and many plants now in bloom, there has never been a better time to take a closer look at the humble garden wall. In this post, we’ll explore ten of the plants you may encounter across Gosforth’s Wild Web. How many will you find over the months ahead?
Colourful Colonists
Walls in Newcastle are often marked by an abundance of naturalised alien plants—those introduced by humans. These opportunistic plants have seamlessly integrated into the urban environment and typically pose few problems. Even better, they often add a touch of beauty to the otherwise uninspiring greys and browns of stone walls.
Perhaps the most common of these is the aptly named Ivy-leaved Toadflax. This tenacious little plant, introduced from the Mediterranean and rumoured to have arrived in Britain as a stowaway on marble statues, has a unique adaptation for colonising walls and structures. After flowering, the seed heads bend away from the sun and towards the wall, eventually finding a crack or crevice in which to deposit their seeds. This tendency makes it one of the few plants capable of spreading vertically up a wall. With its purple, snapdragon-like flowers and distinctive leaves, Ivy-leaved Toadflax is hard to miss.
Another introduction from the Mediterranean at home on our garden walls is Oxford Ragwort. Now, this plant has an intriguing back story in that it was first introduced to Oxford Botanical Garden in 1690 from the island of Sicily. Since then, it has spread to colonise urban areas nationwide and is now a common sight in Tyneside. This species can be told apart from its relative, Groundsel, by the presence of prominent rayed petals and from Common Ragwort by the presence of black bracks behind the flower that extend onto the flower stem.
A third Mediterranean plant is just as abundant as the two species mentioned previously: Red Valerian. Adapted to growing on the parched rock faces and cliffs of Southern Europe, this plant easily transitions to life on our walls. With frothy pink flowers and opposite pairs of pale-green, oval leaves, it is distinctive and hard to miss when in bloom.
A member of the poppy family with masses of trumpet-like yellow flowers, Yellow Corydalis is yet another European colonist. This plant thrives in dark, shaded corners and isn’t bothered by a lack of soil. Originating from the Alps, it is well-adapted to wedging its roots into the gaps in walls. Known in the UK since 1796, it is not a recent introduction and can be quite common in Newcastle’s terraced neighbourhoods.
Brilliant Bellflowers
With their striking blue blooms, bellflowers, or campanulas, are beloved by gardeners and widely grown in gardens across the city. For this reason, they are frequently seen escaping from gardens to colonise walls and other stone structures. Two species, in particular, are quite common and easily confused, while a third is a bit scarcer but increasing. Let’s start with those similar ones first.
Both Trailing Bellflower and Adria Bellflower are superficially similar, as they are both trailing or scrambling plants with blue, bell-shaped flowers. Hailing from the mountainsides of Eastern Europe, they are well adapted to thin soils low in nutrients. Anecdotally, Trailing Bellflower appears more abundant in Newcastle, but you have a good chance of encountering both in neighbourhoods such as Heaton, Jesmond, and Walker.
The key to distinguishing these two is to closely examine their flowers. Trailing Bellflower typically has pale, pastel-blue flowers with deeply divided petals, giving them a spreading appearance. In contrast, Adria Bellflower usually features deeper blue flowers with petals fused along most of their length, giving them a more pronounced bell shape.
A third bellflower that may pop up on a wall near you is the Peach-leaved Bellflower. A popular rockery plant with a nifty ability to seed itself all over, this tufted, upright plant differs greatly from the two mentioned previously. The key feature of this species is its large, ascending broad bells, which do not nod like those of other bellflowers. While not all that common in the wild, it is becoming more frequent and was even spotted on a wall during a recent NHSN trip to Walker.
Spot the Succulents
The final three plants covered here are all succulents, meaning they are well-adapted to life on parched surfaces due to their ability to store water. Of these, one is a British native, while the others are widespread garden escapes. Let’s start with our native species.
Biting Stonecrop is a mat-forming plant common on well-drained ground such as walls and pavements. It features yellow, star-shaped flowers that appear from May to July and fleshy leaves with a hot taste if nibbled—hence its name. Its egg-shaped leaves are tightly clustered together, and its yellow flowers help distinguish it from White Stonecrop, a naturalised garden escape. As its name suggests, White Stonecrop sports white flowers and has more cylindrical leaves, almost like jelly beans. These leaves can be tinged with red where the plant is exposed to high temperatures.
Finally, on our whistle-stop tour of the plants found growing on Newcastle’s walls, we have Reflexed Stonecrop. This plant looks drastically different from the previous two as it is a much larger, straggling plant with linear, needle-like leaves. A similar species, Rock Stonecrop, has been recorded very rarely in the area and looks quite similar but can be distinguished by its flattened leaves and its tendency to lose leaves entirely on the lowest parts of the stem. Most of the time, however, it will be Reflexed Stonecrop that you encounter.
And there we have it, a short account of just some of the intriguing plants you could encounter on garden walls across the city. There are, of course, many more but hopefully, this list inspires you to look closer at walls in your neighborhood. If you do, please consider sharing your sightings as part of Gosforth’s Wild Web here.