Adding new mulch on top of old mulch with newspaper in between

Asked January 7, 2016, 3:57 PM EST

This spring I plan on putting new mulch down in my backyard plant bed as well as a layer of newspaper on top of the old mulch to hopefully choke the weeds and grass that were growing in the bed last season.

My question is what is the optimal depth of the new mulch that I should be laying down on top of the newspaper? I would hate to add too little or too much and ruin things.

Douglas County Colorado

1 Response

The type of mulch and how much to apply depends on several factors: type of garden, type of soil, whether the site is windy or on a slope, so it is difficult to give you a concrete answer. I suggest you check out this CSU Garden Note on mulches to see which mulch you should apply and how much you should apply. I don't think it's a good idea to apply a newspaper layer over an old mulch layer. Rake up the old mulch before you apply an underlayment of newspapers (one to 2 sheets thick). You will want to apply mulch soon after the newspapers so they don't blow away. If you are using a bark mulch, the usual depth is 3 to 4 inches deep.