I haven't got a single tree - but if I did, I would be mulching with shredded leaves. I plan to beg leaves from my suburban friends this fall. You can shred them with a lawn mower or buy a shredder/chipper. Earlier today I bookmarked a how-to page for Leaf Mulching.

Here is a link that might be useful: Making Mulch from Leaves

If the garden you want to mulch is it against the house and have you seen carpenter ants call an exterminator they are most likely in your house too. We have alot of carpenter ants so I have an exterminator treat around the exterior of the house during high activity times. Besides the chemicals they use are actually less toxic than the chemicals you buy at say Lowes or Home Depot. (I checked it out)

I also mulch with shredded hardwood but will change to cypress (if I can find it, I don't like cedar the smell is too strong) but leave about 4-6 " away from the foundation. I learned this living down south and having to deal with termites. But as matriarchy noted I mostly mulch with leaf mulch until it runs out...and I have 2 acres of oak trees. And I still don't have enough.

You could use pine straw I imagine...like they use in the south. I'm not sure, but I don't think the ants would want to bother with it. You can get it in Ohio...I am not sure if they ship or not...but I like pube straw so much that I am thinking of driving to get it if they don't ship! http://www.southernpinestraw.com/
Robin

Sorry for the typo...I really did NOT mean that kind of straw...I REALLY meant PINE straw. SIGH. Wouldn't you think I would read more carefully on the preview???

Robin

Hee hee... I actually googled that to find out what I was missing. Didn't find much that had to do with gardening. Then I saw your typo post. LOL

Pine straw never kept fire ants away when I lived in SC, I doubt it will make a difference with carpenter ants.