How to Mulch Trees

Dave Epstein: Hi. I’m Dave Epstein. This is Growing Wisdom. And Dave Ropes here from Tree Specialist. He has let me play with this nifty tool. This is a soil compaction tool. We’re underneath the canopy here of a maple. And we’re learning a lot here about what’s going on with this tree. Dave Ropes: Yes. I mean, this is a common situation particularly with maple trees with very aggressive root system and very dense shade so it’s very hard to much of a lawn under here. And then what happens is that you get this bare soil conditions which this would drain water and put traffic becoming very compact. Dave Epstein: I think I can figure out how this works, but explain to me a little bit about this. Dave Ropes: It’s just measuring the amount of force that it takes to push down into the soil. And when the dial gets to the red line there, that’s the point at which the soil is compacted enough so that roots physically have a hard time penetrating it. Obviously, you want to have soil that’s loose and fluffy and new roots can grow. Dave Epstein: And what can that do to the health of the tree if the roots can’t go anywhere? Dave Ropes: Well, there are a lot of things. First of all, you don’t get good gas exchange with the growing roots, soil aeration for the bacteria and fungi that we know live in healthy soils. You also get a lot of runoff, the water, without the grass to stop it. No absorption so it just runs off so you end up having very dry conditions. Dave Epstein: One of the things is that people have a lot of those plantains. And you were telling me, they are an indicator of what? Dave Ropes: Of compacted acidic soil conditions and they’ll form that kind of dense monoculture when nothing else will grow there. So that tells you right off of that you get trouble. Dave Epstein: So what do you do? A lot of people say, “I want to grass.” It’s not going to happen, is it? Dave Ropes: Yeah. You’re really not going to have a satisfactory turf growth underneath maple or sugar maple tree. So, we really encourage people to give up some of their struggling lawn and convert it to mulch. Dave Epstein: Do you put the mulch a couple of inches around the tree? How wide do you want this? Dave Ropes: Our New England soil is very shallow and the trees are forced to go very wide, not deep. And so if you’re going to mulch, you really need to treat a rather large are. Dave Epstein: So Dave, underneath that we’ve moved to, the mulch should probably have gone quite a bit further out because… Dave Ropes: These are the roots, yeah. Really, we need to probably double the square footage. Dave Epstein: Alright. For those who I get a lot of questions about this who want to know what to do underneath trees like that, now you know it. Mulch is probably one of your best answers. It helps the tree. And why fight it? You can’t grow the grass anyway. Come back every week for all of our tips and some help here at Growing Wisdom.