Slugs eating tulips

Try some sharp grit or eggshells around them perhaps.

I stopped all treatments and attempts at discouraging slugs many years ago, as none worked very well. I went organic and encouraged wildlife. Between birds and hedgehogs I have no damage from slugs or snails anymore. It took a few years but it all seems in balance now.

I use a bunch of traps interspersed with the plants.

I don't use beer. Beer is expensive. Just 2 liters of water, 1 packet of the cheap bread yeast from Lidl, 1 tbsp. cheap white sugar, 1 tbsp. cheap white flour. Mix it all up, pour into traps.

I make my traps from old plastic jars like peanut butter or (best ones) Ovaltine jars. Keep the lids, drill large holes in the sides of the jars with a hole saw, about 1.5" diameter seems about right, so that you can bury the jars about halfway and fill with the bait mix. With lids on the jars the rain won't wash them away. They last around a week, well, that's my interval for replacing the bait. Just dump the drowned slugs. You can also just bury plastic trays like the ones mushrooms come in (with a little depth, about 2-3 inches) and the slugs'll drown in those, too, but the rain makes short work of the bait water.

Eggshells had no affect, zilch, zip, nada and I used a lot of eggshells. "Slug deterrent" wool, they probably took it and knitted little slug sweaters for all the difference it made. I won't use the toxic baits. Organic baits get eaten by the birds, some of whom have occasionally shown interest in the slugs but not to any great effect. Hedgehogs are a rare site out here. Back in the US we had opossums, they actually worked pretty well to keep the slugs down and we had some pretty scary large Pacific Northwest slugs, bigger but less numerous than what's crawling around here in West Kerry.

Going out in the early morning/after it gets dark gets old really fast esp. as the days grow longer. It needs to be good and dark for awhile. It does work, but you need to do it like every day. I need my sleep so I don't.

I've heard that if you lay wooden planks around the beds, the slugs will congregate there when the sun's out because it's dark and moist. I am going to try that in a couple of places, but with the Irish weather who knows how much sun there'll be.

Haven't tried nematodes. "Nemaslug" seems pretty expensive, my experienced gardener neighbor said it was a fail for him when he did try it.

My bad. Turns out we used quarry sand, not beach sand. If you're concerned with beach sand, rinse it in a pillowcase. Salt won't persist in it.

You don't need a pond. Plenty of cover and damp shaded area will do. Frogs breed in water but spend virtually all their adult lives on land. I've no pond but plenty of frogs in the garden.

We live in a maritime region. Salt in the soil is a thing. And, this year, herself's gotten a 2d crop of tulips for the first time (after the sand was used.) So maybe 'beach sand is bad' isn't 100% the case. Also, being in an Irish maritime region, we get way more wind, rain and wet than the average, including awful salt storms where the waves crash against the cliffs, spewing seawater upwards to be caught by the wind. Might be we get enough rain the salt doesn't actually leach too badly into the soil. The salt on any plants leaves, though, is bad.

As far as eggshells and slugs goes, well, the only way I've found eggshells do any good is if I take a wide loo roll, put a coating of vaseline around the top 1/3rd or so, and dredge that in crushed eggshell. That 'ring' is then buried around the plant with the eggshell barrier at the surface. That seems to keep slugs out for a time. Just spreading it on the ground even in a thick cover is useless, your Irish slugs are brutal little feckers and the only predators we've seen have been the rare hedgehogs.

Plus... snails. Even worse, harder to kill.