I went out again this morning checking my daylilies for snails and slugs. I did find a few of each. Just as my small spray bottle ran out of solution (1 to 3 mixture of ammonia to water), I got the bright idea to take photos. I went to refill my bottle and get the camera but by the time I returned the slug had hidden himself away. So all I got were these photos showing signs left by the slugs and the damage they do. I will try again tomorrow.
Signs snails or slugs have been on this daylily.

Resulting damage done by slugs or snails.

Does the ammonia solution kill the slugs/snails? does it do any harm to the leaves?

Yes the ammonia solution does kill the slugs and snails it comes in direct contact with when spraying. There is little to no residual killing power to the ammonia solution. I have never detected any harm done to the plants and have even read it provides a slight nitrogen boost. I have used this method for several years now on hostas and daylilies and it has managed to keep the slugs and snails under control under prime conditions for slugs and snails, very damp soil most of the year and lots of mulch for them to hide under. I like to spray a good stream on the ground also as close to the plants as I can to try and kill some of the eggs and emerging slugs and snails.

Thank you. Slugs have been here for a long time and do little damage to my daylilies. Snails, on the other hand, have been here only 2 seasons and are increasing every season. In retrospect, I believe they hitched a ride on a potted plant and now are a problem. Another reason to buy only bare root plants.

I had no snails for a long time, then one year out of no where I had big snails, don't see many of those anymore, now mostly just very small snails.

Keep this in mind! Slugs will not crawl over "crusher dust" or dolomite (crushed sea shells-from Aquarium shops). The sharp tiny rocks evidently tear open their bellies! GOOD!! I finally put in Hostas again two years ago, along with daylilies, and not a slug anywhere! Of course, then a deer got through my fence, and then there certainly were no slugs on what had once been Hostas! LOL. I have never tried ammonium spray, so I don't know if it just keeps slugs away, or kills them. I think I will try a mild salt solution spray for other plants because I know the slugs disintegrate right in front of your eyes if you sprinkle salt on them. Yes I LOVE IT!!! Lock me up, I don't care!!!!! LOL.

I tried the ammonia solution spray on my hostas two years ago. Cleaned them up in the spring and sprayed each clump of hostas when their leaves were still curled up into little nubs (which is better for the hosta). It was amazing how much better they looked all year long. I have an area (actually near the hostas) where several daylilies took a hit from slugs I think. I'm going to give that a try on the daylilies this year.

Won't spraying salt solution affect the soil? We use it here to get rid of weeds but only ones growing in paths or gravel as I was always advised it would stop anything growing where you spray it.

Scatterbrain said:Won't spraying salt solution affect the soil? We use it here to get rid of weeds but only ones growing in paths or gravel as I was always advised it would stop anything growing where you spray it.

Salt is one of the original, historical, non-selective herbicides.

I have slugs and snails and the snail especially love to hang out on the daylilies. I don't see hardly any damage though (except the nasty slime trails). I think the reason is because I use paper tags when I do my crosses. They LOVE to eat those! The leaves are apparently no where near as tasty.

I do see slugs on the daylilies, especially after it rains. But typically they don't bother them much. I pick them off and toss them far away since it's only the tiny ones I see on the foliage.