The iris hunter: What to do when voles attack your treasured bulbs

The small ribbon of ground immediately behind the retaining wall in the yard has become the most over-gardened bit of earth in Christendom. It's all I can reach from the wheelchair to which I'm presently confined. The old opium poppies have been pulled up, alchemilla cut back, weeds hooked out.

This intense, close-focus gardening in an area where I grow a lot of special bulbs, showed me plenty I didn't want to see. The ground is mulched heavily with gravel, which helps with drainage and keeps the flowers clean as they emerge. I had some hope, too, that it would deter the voles that love our south-facing banks. Unfortunately not. Among the old foliage and dead leaves, were neat piles of husks, the perfect forms of iris bulbs, crocus corms, the fibrous outer tunics perfect in every detail. But empty. Chewed. Useless.

Next to each little heap was a mocking label: 'Lady Beatrix Stanley' (one of the most stunning dwarf iris ever raised), Crocus cartwrightianus – a memorial to a passion for autumn-flowering crocus that developed when I was writing my book, Bulb (Mitchell Beazley, £30). And next to the labels were the neat holes leading to the wretched voles' living rooms. I could see them perched there, polishing their whiskers, discussing the day's events. "So what did you think of that new crocus? Not quite so good as C. sativus, I fancy. Sativus has an element of the divine. Provided of course, you take it at exactly the right moment." And, by the evidence above ground, it seems a lot of taking has been going on.

Which explains why, despite spending more on bulbs than I do on clothes, our garden is still not carpeted wall to wall, hedge to hedge with alliums and tulips, crocus and iris, erythroniums and fritillaries. Only the autumn cyclamen (C. hederifolium), flowering now in fantastic profusion, seem reasonably safe. Even they get turfed up from time to time by the badgers that come through every night.

So, what's the answer? Well, I'm certainly not going to give up growing bulbs. My love affair with them will last till I die. And I'll certainly replace 'Lady Beatrix Stanley' (available from Avon Bulbs, £5 for five). It's a dwarf (10-15cm) iris, flowering in late January or early February, giving a more substantial flower than, say, 'Cantab', in a richer, more pleasing colour. The falls are spoon-shaped with the lid above them divided in two so that each fall seems to look at you like an exceptionally alert small animal.

This iris demands good drainage, but does well outside as it likes to be cool and not too dry in summer. It's been around since the Thirties, when it was named after the formidable editor of The New Flora and Silva magazine. The bulbs need to go in 10cm deep and about the same distance apart.

I've been wondering, though, while I work out ways to flush out the voles from the sunny bank, whether I ought not to focus this year on bulbs that like damper, cooler growing conditions, less attractive to the mousey tribe. So I'm ordering as many English iris (Iris latifolia) as I can find, similar in some ways to Dutch iris, but flowering later in darker, inkier colours. When I first started to garden, I grew a lot of them. Then they became hard to find. Now, hurrah, six different kinds are listed in The Plant Finder.

They're not actually English at all, but grow in damp alpine meadows in the Pyrenees and northwest Spain (Picos de Europa). The muddle was the fault of a 16th-century Flemish scholar and plantsman, Lobelius, who first saw them flowering near Bristol, where they had probably been brought by Spanish ships from the Cordillera Cantabrica or from the Pyrenees. On the basis of this sighting, Lobelius described them as English iris, an erroneous tag that has stuck. The only iris actually native in this country are the yellow flag iris, Iris pseudacorus and the stinking iris, I. foetidissima.

But once introduced, it became hugely popular with gardeners. By 1788, Haarlem bulb growers were offering 37 different kinds of "English" iris in their catalogues and by 1808, Van Veen & Co of Haarlem listed 47. They fell out of favour with commercial growers because they could not be forced out of season for the cut flower market, like the Dutch iris. It's up to us gardeners to make sure they don't disappear again.

'King of the Blues', first introduced by the fine bulb company Barr in 1898, is a strong, deep blue with a yellow beard. 'Mont Blanc' is almost pure white with only the thinnest streak of yellow marking its beard. Avon has them both at £5 for five bulbs. They are all gorgeous things, in mottled shades of blue, mauve and purple, some as pale as a misty morning, some as dark as ink (but unlike Dutch and Spanish iris, never yellow).

Try them in dampish soil with Lilium pyrenaicum or Narcissus pseudonarcissus (they grow together in the wild), or with sanguisorba and veratrum. They are hardier than Dutch iris and in the right conditions (damper than the ground you might generally choose for iris) will settle and increase. Plant bulbs 10cm deep and 10-15cm apart. If you are more than usually blessed, they may even naturalise in grass, provided it is not too coarse. The late Christopher Lloyd had them growing like this at Great Dixter in Sussex. John Sales, for many years a brilliant Head of Gardens at the National Trust, has also settled them very successfully in grass. So successfully that last week he brought me a clump of his own English iris seedlings. Presents don't come any more welcome than that. Let's hope that the wretched voles stay away from them.

Avon Bulbs, Burnt House Farm, Mid Lambrook, South Petherton, Somerset TA13 5HE, 01460 242177, avonbulbs.co.uk