A Gardeners Forum Forums General Discussion Landscape trials and triumphs Using decorative rock as ground cover.

I am considering using river rock in place of mulch in all of my planting beds. Is there any disadvantage to doing this? Will the rock radiate heat and damage the plants.

To use rock as a mulch it will not provide the benefits of Mulch. It will Not prevent weeds,, it will have to be replaced from time to time as some will sink and will be incorporated into the soil. Unless you use a weed preventive barrier cloth/ between the rock and the soil , But keep in mind also that will make it harder to add plantings or divide perennials with the barrier cloth and the rocks.
However you can make a rock garden, as I did,, I used heavy black trash bags,, overlapping them as I laid them down, and fill an the area with rock and planted perennials and a couple of benches,, the perennials I used do NOT spread,, so I didn't have to worry about tubers and/or rhizomes developing underground to promote dividing them. IF you use rock,, know what kind of roots your plants will have,, use a weed barrier cloth or something similar, Tho rocks do have a nice look as opposed to mulch,, you also need to research the plants they will complimenting.
The plants/flowers I have are coneflowers, lavender, pineapple sage,blanket flowers, dianthus, African orange bulbine, roses, and some succulents, and they all do fine in this 100 degree Texas Heat. I did this 5 years ago,, and the last couple of years I have been pulling weeds ,,, a lot of weeds SOooooo,, that said,, weed pulling is a given eventually , and the heat radiated from the rocks if there IS any,,, doesn't affect the particular plants I have.