What kind of mulch is it? What kind of climate do you live in?

I agree with rgreen. Unless it is getting way too deep or there are issues with pests or fungal diseases in your area if thick mulch is used, I'd just add enough on top to get the thickness and look you want. It feeds the soil as it decomposes which is a good thing.

I just came across this piece: www.thisoldhouse.com/more/may-mulching

I live in Central PA.

You don't need to add more unless it's getting thin in an area. If it's built up in one area, don't add any there for a while.

And you don't need to remove some just to make room for 'fresh" mulch.

It would be like changing the air in your tires. :-D

Mulch ado about nothing? Leave the old, apply only as needed.

tj

What kind of mulch has been put down in the previous years? I asked that question for a reason.

Can you post pictures of the area where the mulch is getting allegedly "built up"?

It strikes me that, if I were a landscaping company, a yearly contract to put on new mulch would be good business, but a yearly contract to "clean up" some of the "old mulch" and then put on some nice "new mulch" might be even better business. Maybe I can sell that tired old mulch to the next customer as compost.

Don't have any pix to show right now. I decided to go with removing some of the mulch. We will only need to do it every 3 years or so. We'll see how it goes. Thanks for chiming in!

An article in an issue of Fine Gardening magazine on a 9 year study of mulching by 2 researchers from Michigan State University stated they found a mulch depth of 6 inches was what is needed to be most effective. There is a whole segment of people out there that have a firm belief that mulch should never exceed 2 inches and that simply is not enough.

If the person I loaned that issue to ever returns it I could give dates, but visit your local library and look for an issue in early 2016.

I find mulch layers of 6" to be suboptimal in the areas of my garden where I am growing 6" tall plants, or any areas there the plants have leaves less than 6" above the ground, or any areas where there are woody trunks of shrubs or trees.

"As deep as you can reasonably get it without burying the plants, never piled against trunks or stems, not to exceed 6" deep" is probably a better spec.

Never, ever pile mulch against tree and shrub trunks.

Common sense should also play a role in gardening and should lead a gardener to not attempt to bury plants simply because someone indicates a certain mulch depth is most effective.

We've been getting new mulch every year for probably 9 years and have never gotten any removed, so that is a VERY deep layer of mulch we now have!

It's mulching season here, and all over town there are trees along the streets where maintenance crews have piled up mulch in a little mountain around the base of each tree, burying 6-8" of the trunk. Sigh.