Snails’ sense of smell.

BenCotto

I had little luck with the petunia wave Blue Denim seeds which I sowed earlier in the year - only six germinated and so I was not happy when, while hardening them off, one was eaten by snails/slugs. The rest are now protected by copper bands placed around the plant pots which seem to be working.

It doesn’t stop me doing snail patrols on damp nights, such as today’s, and though the Blue Denim petunias were fine, there were 15 snails on or very close to the terracotta pot containing bigger Red Velour petunias.

How do snails know they’re there? From how far away can they detect a petunia dinner? I really find it hard to destroy the things so like to give them a fighting chance by lobbing them way up the lawn yet hoping badgers will do the dirty deed and make short shrift of them. Do badgers eat snails? Or foxes, though they’re less frequent visitors? 

edhelka

A good question. I have three hostas, all in different parts of the garden. I also have some other plants that could be attractive to them - lupins, delphiniums, petunias, leafy vegetables... but they only find and eat hostas.

pansyface

So many people react to slugs and snails with a “yuck” and a grimace, which is a pity because they are interesting creatures.

Here is a nice, non hysterical, calm and informative article about snails.

http://agresearch.montana.edu/wtarc/producerinfo/entomology-insect-ecology/EasternHeathSnail/GermanFactSheet.pdf

For help in the garden, you need a thrush for the snails and a blackbird for the slugs.🙂

Posy

I don't know the details but there was some research that showed they have a 'homing' instinct and will return to their patch. And every gardener knows they have distinct preferences, so they must sense direction. Their eyes are not especially good, I think, so smell must be the answer.

They ARE interesting and we shouldn't be hysterical, but they are also very destructive in a garden. It's our fault in a way - we provide all the things they need in a small space and then complain when they breed successfully. We also bring in foreign varieties which flourish in our climate. If our gardens were like meadows there wouldn't be so many slugs, but I am afraid that if we are to garden, we cannot rely on thrushes and blackbirds. At least, not without a plague of those, too!

josusa47

I've read that the homing instinct of both slugs and snails extends as far as a quarter of a mile.  So it really is futile to throw them over the fence.  And there is a good evolutionary reason why they don't emerge until their avian predators have gone to bed.

I remember a question on GQT about protecting hostas from slugs.  One member of the panel wryly advocated protecting salad crops by surrounding them with hostas.

pansyface

Hedgehogs too.

A laager of hedgehogs would do the trick.

Nollie

It always astounds me how any creature finds ‘it’s’ plant. No Berberis around here for miles, its all farmland, yet I plant some and the Berberis Sawfly soon found them. Do they send out spotter/sniffer teams, quartering the countryside then letting all their friends know when the target is located? Not that I have many, but I don’t think I’d actually seen a snail here until I planted a dahlia...

Fire

P, it's a good question. I assume it must be smell.

Lizzie27

Just found a snail busy munching inside a white bearded iris - 2 ft up in the air!

Skandi

You can have a bit of fun with a large slug and it's homing instinct. Take a big slug I've used leopard slugs as I don't kill them. Take it from it's home put it in the middle of the lawn or somewhere (do it on a damp day don't want to kill it after all) and put some obstacles in front of it. We used a line of salt on a paving slab pots of water etc. It will successfully navigate round everything to get home.

In my last house I had 1000's of spanish slug crosses huge beasts and I had hostas, and I had one hosta they didn't eat. in this house I've only found little banded snails and the one hosta that is here is being eaten. I may have to go get some of my old non edible hosta!

josusa47

Can't bear to kill anything, so when I moved to this house I rehomed the hostas I found in the garden.