[hubballi]

I clocked a guy who grew nothing but hostas on gardeners world a few years ago who said he kept the plants 100% slug free by spraying the upcoming shoots with garlic cloves boiled in water. Well, I can say it works 100% for sure. But until a couple of days ago it hasn't been touched since sprayed at the begining of spring. What I find interesting is about this time every year since I started the spraying the slugs and snail suddenly start feasting on the leaves. I gave a fresh spray yesterday but it clearly has had no effect.

Any theories why this only works for so long ?

[fatcat1955]

The rain washes the garlic spray off, it is not absorbed by the leave's.

[Wild Willow]

I've put crushed eggshells around my "delicate" plants...I'm hoping that works.  I've never tried garlic spray before; I've heard garlic is good around carrots to confuse carrot fly though.

[hubballi]

It can't be washed away because I sprayed them months ago and it has rained lots since then. Unless it's a few rains that have worn the garlic down but how do you explain a fresh garlic spray not working ?

[mumofstig]

Perhaps they simply get used to the taste or smell - if they can smell?

The same as we get used to garlic on peoples breath if we go to live in somewhere like Spain