Country diary: The Algerian iris is my madeleine

Many of the plants in my garden hold memories, collapsing time as vividly as Proust’s madeleine. The smell of a Cheddar pink is me in my parents’ garden, lying on sun-warm grass at the edge of a border. The bitter almond of viburnum is midwinter days in the first garden I made. Pink-trumpeted daffodils, dark red hellebores, a silver-leaved cyclamen – all are gifts from people no longer alive that remind me of them every time I see them.

The plant with the most direct link back to my childhood is flowering now against the south-facing wall of my house. There, nesting in an untidy sprawl of leaves, the mauve-blue of Algerian irises is so unexpected in winter. The colour of native bluebells, the fragile-looking flowers have purple lines and a central yellow band guiding down into white throats. Blooming since late December, they have continuously budded, opened and shrivelled, each lasting just a couple of days.

One of my earliest memories is of these irises, their colour shining from messy clumps in gravel below a brick wall. Theirs was the first botanical name I learned without realising that that was what it was. Iris stylosa, as it was then, was a lilting, many-syllabled word, no different to any other that I was learning. It wasn’t until much later that I realised it was a scientific name comprising genus and species. Now it is known as Iris unguicularis. I still prefer the older sound.

In the rain shadow of the house, the plant’s rhizomes have congregated into a mound, keeping it drier still. It received no water for months last summer, and this is why I am able to grow it in a Northumberland frost hollow. The flat, strap-like leaves with their tough parallel fibres can be woven into baskets. In pale February light, their shadows drift across the sandy-coloured wall. A great tit chirps, a pigeon croons, the wind ruffles the irises. Ignoring those that have been nibbled by voles or slugs, I pick a few buds to open in the house. Honey-scented and fleeting, their colours are astonishing, evoking clear north African skies.

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