Hostas are one of the most reliable plants you can grow in an Irish garden. They thrive in the shade, they tolerate our damp conditions, and the range of leaf form and colour available now is extraordinary. The problem is that everything that makes our climate good for hostas also makes it good for slugs. A wet May evening in Ireland is as close to perfect slug weather as you will find anywhere in the world, and hostas are among their preferred targets. The damage, when it comes, is immediate and disfiguring: ragged holes punched through leaves that were pristine the morning before.

The instinct many gardeners reach for is the pellet. For years the organic ferric phosphate pellet was presented as the responsible choice, the safe alternative to metaldehyde, approved for organic growing and harmless to wildlife. I recommended them myself for a long time. But the picture has become less clear. There is now credible concern, acknowledged by the RHS and supported by independent research, that the chelating agents used to make ferric phosphate soluble enough to kill slugs may also have negative effects on earthworms and other non-target species. The pellets are also cereal-based and attractive to birds, and any bird or hedgehog eating a poisoned slug is potentially affected by what that slug has consumed. The honest position at this point is that pellets, even the organic ones, are no longer something I would reach for first. The garden is an ecosystem, not a battlefield, and the goal is balance rather than elimination.

If your hosta is growing in a pot, which is very common in Irish gardens where paved and patio spaces are the norm, the most practical solution is copper tape. It is a self-adhesive tape, copper on the outer face, that runs around the rim of the pot. When a slug attempts to cross it, the copper interferes with the mucus on its foot and it turns back. It will not harm the slug, it will not affect birds or hedgehogs, and it works consistently once the tape is fitted properly and there are no gaps. Check that no leaves are drooping to the ground beside the pot and providing a bridge that bypasses the tape entirely. A pot treated this way can be left to fend for itself with very little further intervention.

For hostas in the ground, the equivalent approach is a sheep's wool barrier. You can buy it in pellet form from most good garden centres, or, if you are near farming country, raw fleece works equally well. Lay it in a ring around the planting. Slugs cannot cross it comfortably and will turn away. The wool breaks down gradually into the soil, adding organic matter as it does. It is not a permanent fix and needs refreshing through the season, but it is entirely benign and will not harm anything that touches it. Improving the soil structure around your hostas over time also makes a real difference to overall plant resilience, and a well-fed hosta in good soil will recover from limited slug grazing far more readily than a stressed one.

The longer-term answer is to make your garden less hospitable to large slug populations by making it more hospitable to the creatures that eat them. Thrushes and blackbirds are among the most effective slug predators you have, and a garden with good shrub cover, a reliable water source and minimal disturbance to the soil surface will attract and retain them. Hedgehogs, which are under considerable pressure across Ireland due to habitat loss and road casualties, will patrol a garden at night and consume significant numbers of slugs. If you have the space to leave a small gap in your boundary fence or wall, that single act does more for slug control than any pellet regime. Frogs and toads also contribute, particularly in gardens with damp corners or a small pond. None of this is dramatic or immediate, but over a season or two the balance shifts noticeably.

The variety of hosta you grow also matters. The glaucous blue-leaved hostas, those with a waxy surface bloom on the leaf, are substantially less attractive to slugs than the thinner-leaved green and yellow varieties. If you have a particularly difficult spot and are replanting, it is worth choosing accordingly. That said, even the most slug-resistant variety will need some protection in a wet Irish spring, particularly in the weeks immediately after emergence when the new growth is at its most tender. That is the critical window. Get your barriers in place before the shoots come through, not after the damage has already been done.