The thing to do prior to planting is to ID the whatevers. Any chance of pictures?

you really shouldnt be using any of the chemicals on FOOD ...

regardless.. the one thing your story lacks.. is that what you found is having any negative impact on the plant ...

you state that what i know as an annual [up here in z5] ... wintered over.. looked great.. and you didnt even know there was a problem until you looked at the roots ... so i simply ask ..

are you really curing a problem??? or just looking for trouble???

dont treat things.. unless a problem is properly ID'd ... not only the bug.. but that the bug is actually creating a problem ...

and yes ... some slugs do winter over in mature form.. as do gelatinous eggs about the size of a pinhead ...

my slugs can be killed .. on contact with 10% vinegar or ammonia .... no real need for chemicals.. just a constant spraying with the vinegar ... constant meaning you spray your plants at least once a week to check and control populations ... this is not a once a season .. throw some stuff around.. and hope for the best job ....

there should be many posts and a FAQ in the hosta forum.. where we hate slugs with a passion ...

ken

Here is a link that might be useful: link

Jamestrix, your 'worthless' Elementals slug and snail killer has the same active ingredient, at the same percentage as Sluggo. This would NOT be the appropriate time to apply a bait, however.

Some species of slugs hibernate during the winter, and may follow root system channels several inches deep.