Rose growing in rock mulch. Q. I have moved into a house that is about 3 years old with a wide variety of plants.  I have read your articles against rock mulch but I don’t know which of my plants can tolerate the rock mulch that is already there and which ones I should pull the rock away and use wood mulch.             I come from Northern Utah and do not have a clue how to handle these types of plants and all this rock. A. I am not against rock mulch but it should not be used for everything and not all plants should be planted into rock mulch.  My personal philosophy on desert landscapes focuses on using appropriate mulches for plants which can tolerate those mulches.              Generally speaking, those plants which originate from arid or desert environments can generally handle rock mulches.  Those plants which do not originate from arid or desert climates probably should not be planted in rock mulch.  There are always exceptions which never help when you are trying to make rules. Photinia growing in rock mulch.             The problem is that we intermingle desert plants with non-desert plants and then we use rock mulch around everything.  Those plants which can tolerate the rock mulch end up, over time, to do all right.              Those plants which are not true desert plants tend to decline and fail over time.  Plants such as bottle brush, photinia, Carolina cherry laurel, Japanese blueberry, butterfly iris, mock orange, and others usually begin to decline in 4 to 5 years after they are planted as soil amendments used at planting are depleted.              If you want to learn how to handle nondesert plants in rock mulches please visit my blog and search this topic. Bottlebrush growing in rock mulch.             The other reason for decline would be improper watering.  Make sure you get your irrigation intervals and the amount that you apply each time to be adequate for the plants.  Improper watering will cause plants to look terrible as well.