AUSTIN (KXAN) — There’s more to the shredded bark and pieces of wood you see scattered over flowerbeds everywhere. In fact, there are quite a few benefits of the discarded tree pieces, commonly referred to as ‘mulch’.

Not only does mulch protect the ground and surrounding vegetation, but it also serves as a water filter for plant life and runoff.

Meteorologist Kristen Currie spoke with Denise Delaney, a horticulturist with the Austin Watershed Protection Department, to get the details on the practice of mulching. You can read the interview below to learn more.

Kristen Currie, KXAN News: Denise, what is mulch, and what are some of the important qualities of it?

Denise Delaney, Austin Watershed Protection Department: Mulch is a type of organic material that you put on top of the ground, to help protect it in many ways. It’s very common in landscaping, you see it everywhere. But the benefits are one from a water quality perspective as it prevents erosion and keeps the soil from washing away. It also helps keep weeds down because weed seeds need light. So if you’ve got the mulch on top of those seeds, then they’re not going to germinate and you’re going to have fewer weeds. It also helps reduce compaction. And it helps keep the soil temperature even. There are so many benefits to it.

Kristen Currie, KXAN News: Are there certain types of mulch we should be looking for? For our backyards and flowerbeds?

Denise Delaney, Austin Watershed Protection Department: We recommend that you, in most cases, use organic materials like bark mulch or shredded hardwood mulch. Or if you can find pecan shells, anything that’s organic. They usually have them bagged up at the places where you buy plants.

Kristen Currie, KXAN News: What about the timing of mulching?

Denise Delaney, Austin Watershed Protection Department: [January] is a great time to do it. You want to keep it about two to three inches deep. Sometimes that shredded mulch gets matted down. So you might need to go out there and fluff it up a little bit with the rake. You want the water to be able to get through the mulch down to the soil.

Kristen Currie, KXAN News: How often should we be re-mulching? Should we do it once a season? Once a year?

Denise Delaney, Austin Watershed Protection Department: Well after the first time you do it, check it again six months later and see how it is. Some of the mulch breaks down quicker than others. So you’re going to need to add to it and also depends on a lot of the conditions that are around it. But you shouldn’t need to do it more than once a year to top it off.

I know with the Christmas tree recycling you can go pick it up. Now that mulch is going to be pretty rough cut, you know, this is going to be the Christmas Trees, I would use that mulch like in an outer natural area, more so than maybe right in your front yard. I’m not saying you can’t do that, but it’s just going to be a little bit different than what you know you get at the nursery.

Kristen Currie, KXAN News: When mulching, do you go right up to the trunk of the tree and the stem of the flower? Do you leave a little room or is it just everywhere across the beds?

Denise Delaney, Austin Watershed Protection Department: I’m so glad you asked that, because it’s really important to keep it three to five inches away from the base of the plant, whether it’s a tree or a shrub, because when that mulch stays up against it, and it gets moist, and then it can rot the bark. And that basically cuts off the plumbing of the tree. And you don’t want that. It can build up. Just get down just pull it away from the base of the tree or the shrub, make a little base, and maybe to help catch water. A lot of people just mulch right around the ring of the tree, but you want to go out as far as you possibly can to the dripline because those tree roots are competing with whatever’s growing under the tree. The tree is much happier just having mulch underneath it so it can get all the water and nutrients.