I have never had any unreasonable problem with them under the card board. But once I put it down, I put down the mulch and it stay there until it rots. I dig through it to plant. If you move just mulch aside you'll find slugs and roaches to some measure. I haven't found cardboard to make it any worse. :o) And it's a great idea to keep it out of the landfill.

I'm in a different zone - not sure if that matters .
Have never seen slugs or cockroaches under cardboard .
I use a lot of cardboard and have had very good results -
as long as you put plenty of organic matter on top ,
just as katkin said .
Just leave your cardboard in place and don't look !

Thanks very much for your responses, Kat & Gatormom.

I pulled some of that cardboard up yesterday, (too late for your "no peeking" advice) and there weren't any slugs hiding there. So I pondered that I have not noticed MORE slugs (or dreaded roaches for that matter) since first utilizing cardboard in the garden this summer...when I joined the forum.

However, I had a mandatory clean out of my pot ghetto last weekend (neighbor trimmed the hedge). The number of slugs and CTF's attracted to plastic pots were positively horrifying. Most of my plastic pots went out to the roadside but I culled plenty to soak in bleach/water and scrub. I have raw red hands to prove it!

My well respected friend's solution to kiling grass was to use a black plastic trash bag. I think worms love cardboard and beautify our sand.

I'm with you, keep the cardboard, reject the plastic or keep it clean and dry.

Your advice is very well appreciated, thanks once again!

Whenever possible you can take the plastic pots back to nursery or plant sales and recycle them. They take years to break down in the landfill. Big tree hugger here. lol :o)

I'm with you Katkin, was hoping someone in the neighborhood would pick those pots up. Our 'hood is good about garbage pickin'! I know some of the pots were recycled, but I'm not sure if all of them were. Thanks for your very worthy input!