I Tried Using an Old Sweater to Stop Slugs Eating My Potted Hyacinths – Here’s What Happened

I’ll try almost anything once when it comes to stopping slugs. Even if it's something as daft as digging out an old sweater and dressing my plant babies up like their my actual human children.

Yes, like most gardeners, I’ve done pretty much everything (short of using chemicals) to stop slugs.; crushing up eggshells, sprinkling coffee grounds, even slipping out at night with a torch and muttering hexes under my breath as I relocate the worst offenders.

Annoyingly, nothing has worked, so I finally succumbed to my husband's advice: stop growing things that slugs want to eat. Last fall, though, I forgot and filled a pot with hyacinth bulbs... and remembered a few weeks back that all of that tender new growth was doomed to be mercilessly shredded overnight unless I acted fast.

Enter stage left, then, the old sweater.

Why Would a Sweater Stop Slugs?

As ever, you can blame Instagram for this one – although I found the tip via a very reputable source in gardening pro Sarah Raven.

"Have you ever tried using Hortiwool as a slug deterrent? Made from 100% British wool, it comes as large pads that can be ripped up and then laid around your plants," read the post.

Wool as a slug deterrent? The logic behind it is simple: slugs and snails dislike crawling over wool fibres, making it a natural barrier to protect your plants. So much so, in fact, that there are even products like Hortiwool (made from 100% British wool) designed specifically for this purpose.

I didn’t have any Hortiwool to hand, but I did have was an old wool sweater I’d shrunk years ago in a laundry mishap and never quite found a use for. And because I am, at heart, a slightly lazy gardener, I wondered: instead of cutting it up into strips or carefully placing fibers around plants… could I just upcycle the sweater itself?

At the time, my potted hyacinths were just starting to break free, their lush green shoots pushing up confidently, ready to become a tasty little slug buffet. So, not really expecting much, I took my old sweater (crucially, 100% wool. This part really matters, as synthetic fibers won’t have the same effect) and pulled it over the pot like a cozy little cover.

I tucked it around the base, leaving the shoots poking through the neckline, and I’ll be honest: it looked ridiculous... yet somehow oddly promising at the same time.

Normally, I’d expect to see signs of slug damage within a day or two, but after several days… nothing. The leaves were intact. The soil surface, usually a hotspot for nighttime visitors, seemed undisturbed.

Obviously, I can’t claim this was a perfectly controlled scientific study. Gardening rarely is. But the difference was noticeable enough that I paid attention, and kept watching, delighted, as the hyacinths made it all the way to blooming stage without nary a nibble to their name (they've just started to turn over, actually, and they're completely intact).

It makes sense, I guess. Slugs rely on a layer of mucus to move, and they prefer smooth, moist surfaces. Wool, on the other hand, is dry, fibrous, and slightly abrasive – a less violent version of crawling over hot coals and broken glass, maybe.

Still, while my “sweater as a pot cover” method was basically free and worked brilliantly for a container, it’s not the most practical long-term solution for everything.

Slug Deterring Essentials:

Inspired by my research, I’m planning to cut up another old wool jumper into strips and weave them around my vegetable seedlings (yes, I've gotten a little cocky and planted some leafy greens; my husband is just burning to launch into a tuneful 'I told you so' ballad, so wish me luck).

I’m also planning to try a proper wool product like the UK's Hortiwool, just to compare results and see how it performs in a more traditional setup.

Will I be dressing all my pots in knitwear from now on? Probably not. But will I ever throw away a 100% wool jumper again? Absolutely not. Hey, if it can keep my hyacinths safe from slugs, it’s officially earned its place in the garden shed.