This morning we are out mulching all the areas around the clubhouse. Dark shredded hardwood mulch as shown below, adds great contrast and has had time to properly decompose. Many times woody materials have not had the proper time to decompose and need nitrogen and time to do so. If you were to mix fresh chips, or woody chips with your older material it would bind up much of the nutrients while decomposing. This could cause your soil to lose proper fertility for a season or more!