The tatty passageway by the side of my house

Dear reader, please ignore the hosepipe, the bags of compost and the other paraphenalia that are cluttering up the side of my house. In the photo above, Greater Celandine and Yellow Corydalis grow, along with a couple of intrepid Buddleia, in conditions of near total darkness, and the scrappiest, most impoverished soil that you can imagine. They have appeared without any help from me, and have thrived where nothing I’ve ever planted has lasted more than a few weeks . So, what’s the story with weeds?

Many of the weeds in London are ‘aliens’.  Just as London  attracts people from all over the world, so it has a plant population that comes from many countries. Some plants have ‘escaped’ from gardens that they were planted in. Some have survived as seeds in shipping containers full of fruit or in the bellies of airplanes carrying goods from overseas. Some are not just tough but beautiful, and many of them have contributed greatly to the biodiversity of our city streets. I decided to take a walk around the block, to see what was growing in my half-mile territory.

Greater Celandine – a cure for warts?

Greater Celandine flowers early, with flowers that remind me of a buttercup, even though it is in fact a member of the poppy family. It is  thought to have been introduced by the Romans, who thought of it as a medicinal plant – the orange sap is said to be a cure for warts. It was also said to be a cure for eye infections, but actually it was a surefire way of giving the patient conjunctivitis or worse.

Another great survivor is the Yellow Corydalis.

A Yellow Corydalis surviving in a tiny nook in the wall

It came originally from the central and eastern Alps, so it isn’t surprising that it is comfortable in a rocky, nutrient-poor home. It was imported as a cottage garden plant, because it has a very long flowering period, but it has jumped over the wall and headed off into the big city. One survey in South Essex found it in eighteen percent of all the walls in that part of the country. And how pretty it is, with its clusters of elongated yellow flowers.

The long, bell-shaped flowers of the Yellow Corydalis

I like to think that maybe the graffiti artist on this wall chose his colour palette to complement the blossoms….

Yellow flowers, yellow graffiti

Enough of all these yellow flowers! As I approached East Finchley library, I discovered this little beauty growing against the entrance to the car park

Common Field-speedwell

The Common Field-speedwell is also known as the Persian Speedwell, and it originated in the mountains of the Caucasus and Northern Iran. I am starting to sense a theme – many of the plants that live on our streets were originally from mountainous areas. This makes perfect sense. Mountain soils are impoverished, thin, and subject to extremes of weather – lots of bright sunlight in the short summer, cold and rain for the rest of the year. As far as these plants are concerned, a little crack between paving stones is perfect.

Now, here’s another blue flower.

Green Alkanet – a cheap henna substitute

This is a Mediterranean plant, tough, hairy-leaved and prolific. It produces a red dye from its roots, which is used in southern Europe to colour oil and to deepen the colour of cheap red wine.  It is now one of the commonest ‘weeds’ in my little half-mile patch, but I don’t remember it at all from my childhood in East London – a possible indication of the local nature of many plants, and also the way that plant populations change over time.

I can’t talk about alien plants without giving a nod to the greatest of them all.

Buddleia – a ‘Harbourage of Tigers’

Buddleia is another mountain plant, from the scree slopes of the Himalayas. An early visitor to China reported that the buddleia thickets on shingle beside the Satani river was ‘a famous harbourage for tigers’.I have sometimes passed areas of wasteland where the buddleia has formed honey-scented forests, full of the lazy buzzing of bees. These are unique urban woodlands, magical places. Furthermore, they provide a rich source of nectar, and Buddleia may well be responsible for the survival of many insect species in urban areas

Buddleia was introduced into Europe in the 1890’s by the French missionary Pere David, and imported into the UK a few years later. It has light, airborne seed, and quickly escaped, colonising wasteland and, more particularly, railway lines. Every passing train helped to waft the seeds a little further along the line and the clinker that the railways lines rested on was a perfectly acceptable replacement for the mountain slopes of home. I have seen an eight foot tall buddleia growing from a crack in the soot-soiled walls of Liverpool Street Station, where there could not possibly have been more than a few spoonfuls of soil.

My attitude to any plant that appears in the garden is to let it be, at least initially. I have been blessed with all the plants described here, plus comfrey and elecampane, ivy and dandelion, forget-me-not and great willowherb. It seems to me that the division between weeds and ‘proper’ plants is a purely arbitrary one. If a plant is favoured by wildlife, if it is pretty or interesting, I am happy for it to stay. On a grey drizzly spring morning  the unexpected sight of a butter-bright Celandine can seem like a kind of grace.