Rock Mulching – The Best Mulch Technique Ever?

Rock Mulching With Leaves Is The Best Mulch

I’ve written already about the best mulch types to use in your organic garden, but here I’ve put together a video that shows a rather amazing rock mulching technique I didn’t talk about before.

If you have certain bigger plants that are special to you, like a new fruit tree for example, you can use rock mulching with leaves to make the best mulch for improving the soil extremely quickly, resulting in amazing plant growth.

Place a few inches of leaves – which I’ve already shown are the best mulch type – around the root zone of the new tree. Cover those leaves with round stones or flagstones that are small enough so that you can handle them, but big enough to cover some of the leaves.

Doing this rock mulching technique facilitates rapid breakdown of the leaves. They may take 6-8 months to break down normally, but the rock mulch might bring it down to 2 months or so.

Rock Mulching Success Tip

The key to success here is doing it a few times. Yes, you have to remove the rock mulch by hand every couple of months and apply more leaves and place the rocks back by hand. The first time, the leaf mulch will disappear quickly and that will be interesting enough. But subsequent times, you’ll begin to notice a thick layer of worm castings where the leaf mulch once was.

This rock mulching technique is a bit of work. Not much, but it might take 15 minutes to do a tree. It’s not a practice most of us will wish to do long term, but we may want to do it for the first growing season to give the trees an incredible boost. To me, this is the best mulch technique ever.

I show how it’s done in the video.

YouTube video

Click for video transcription

This transcription will have some mistakes because it is partially automated.

Hey guys! It’s Phil from and today I’m going to show you, to do something called rock mulching. First while I’m standing by my garden here I might as well show you the progress, things are starting to grow.

I have some tomato support, you can see it up around there, there’s my little path and I got a nice new little sidewalk in here and things are starting to grow. But still not much exciting going on it’s little bit too early in the spring and it’s been cold and rainy and so we need some warmth for things to really start taking off but I’m pretty excited about this garden this year.

So rock mulching. You know, I don’t generally recommend you using a stone or rocks as a mulch in your garden and the main problem with that is that they don’t let organic matter be recycled back into the soil which is one of the most important goals for us in the garden is to improve the organic matter content of the soil.

So that’s gonna be in the fall, we want to have the leaves that fall from the trees and the plants, we want them to be incorporated back in to the soil like nature does right every fall.

We want to bring compost in every year or a couple of years and things like that. So stones stop all these process from happening and they just, they just stop all the nutrients cycling and organic matter replenishment process in the soil.

But there is one time that I, that I used rocks and it’s called rock mulching for some reason which to me just sound mulching with rocks but it’s not. What it is, is it’s, oh! That’s a nice lilac out there, coz it does not look as cool in the camera. I haven’t notice that yet.

Sorry I got distracted so, so rock mulching is when we, usually around a very important new plant like a young fruit tree or something that we have, you make sure you have a nice bed around the tree.

Put down a bunch of leaves like a few inches of leaves on that bed and then put some rocks on top, not little rocks but like bigger rocks or flagstones which I’ve done and I, I, here I can show you because I have done it to a pear tree here.

Well, I actually show you that coz I was recording this yesterday in a video for the academy. I so, I’ll show you the process of, from start to finish, so what happen is first you make sure the bed is good then you put this nice layer of leaves in there, a few inches of leaves then you cover it up with rocks and what happen is normally those leaves would take, you know 6 to 8 months to break down something like that.

But with the rocks on there it happens in a couple of months and what that means is that I can add another few inches of leaves in a couple of months; and I can do that a few times this year and that’s really where you get the benefits by doing this a few times in a year.

So the rocks really, it’s like they’re, it’s like they’re making these leaves compost much more quickly, improving the organic matter content of the soil and people have proposed different reasons why the rocks might do that.

You know, it could be that a, that just the pressure exerted to the leaves get them more in contact of the soil food web and the earthworms and molasses and break down faster. It could be that the rocks are for protections for earth worms coz there’s certainly an explosion of earthworms under there once this rocks get on there.

It could be that they, you know the heat that the rocks get during the day from the sun is radiated back out at night allowing for a more smooth, a longer breakdown by the soil food web and which is more heat in there so there’s a longer work day for them.

Could be that there’s, there’s definitely gonna be more moisture in there with the rocks there to hold the moisture in so I, it’s probably all of these reasons together, I’m not sure but I do know that these leaves are gonna disappear very quickly and what’s gonna happen is by the end of this year when I’ve done this a few times the soil is going to be beautiful under their full of worm casting and it’s, it’s gonna be a rich beautiful soil.

And I expecting at the top growth is gonna be, when I’ve done this at the past the top growth is going to be nice and I’m hoping will get some pears here for the first time, nice edible pears, and so that’s, that’s rock mulching.

You know it’s this way that we use rocks to help facilitates the breakdown, the fast breakdown of leaves on a very important tree or if you’ve planted a few tree or a small orchards like that.

I think that’s all I wanted to talk about today about rock mulching. Oh! There’s another lilac, I, I gotta start looking around here more and I’m at my parents place.

So, so that’s all so if you haven’t picked out my 15 vital lessons from, for becoming a better organic gardener you can do that at and other than that I hope you can get doing some rock mulching.

You know obviously the fall is when you, your leaves are going to be there but if you have some left over like I did you can start this in the spring and do it a few times this year. So I hope you have a good rest of the day and I’ll be back next week talking about something else.

Any questions about rock mulching to make the best mulch for your organic garden? Let me know below.


  1. Great video. Can I use oak leaves?

    1. You can definitely use oak leaves (there’s no problem with acidity oranything like that), but they will take longer to break down and one of thenice things about this method is using leaves that break down more quicklyso that you can repeat the process several times in one season.But if oak leaves is all you have, go for it!

  2. Thank you Phil.  This is a great method and I will be using it on our food forest at the garden.  I will also be recommending your book for our seedsaving collective. Cheers and thank you for the wonderful info and service you provide.  Cylia

    1. Thanks Cylia. If you get a chance, take before and after pictures of thesoil and top growth of the trees you rock mulch. I’d love to see the resultsafter a few rock mulching sessions are done.

  3. I like it a lot. It is a simple way to mulch a new little tree to your yard. I take it that it works for bushes as well as established trees. Also have you done any work with what is called the worm tower. You can put worm tower in the search area in youtube and different videos will come up about the worm tower. The lady form Australia  has a nice video on the youtube about worm towers. I thought about giving it a try. What are your thoughts about the worm tower concept.

    1. Ya, the worm tower looks great. Or you can just bury your food scraps 12 inches down in different places around the garden.

  4. I’ve been reading through your 5 favorite fertilizers or biostimulants and I’m surprised earthworm castings aren’t on the list. What are your thoughts on worm castings as an additive? Also, all your favorites are mainly foliar fed. I love to foliar feed too but isn’t the motto, feed the soil and the soil feeds the plant? BTW, you have a very informative site! Excellent job.

    1. Hi Steve, yes worm castings and other composts are amazing, and even more important than my 5 foliar fertilizers. I just consider compost in a league of its own.

  5. Shall I put rocks around the roses trunk or shall I leave a soil space around the trunk. also can I put rocks over a mulch?

    1. You can put around the trunk. I wouldn’t have them touching the trunk, but close is okay. And yes, you can put over a mulch.

  6. i don’t have many rocks or flagstones readily available, but as crazy as this sounds, do you think tiles would work instead of rocks, I have plenty of those i could try.

    1. Yes, that could work. Some tiles may be toxic, depending on how they’re made, but if not, that would work well.

  7. Thanks for the great information! How can I extract good minerals found in the rocks in the liquid form?

    1. You’d need a way to pulverize the rocks into a powder. Then you could mix that powder in water to make a liquid fertilizer. Even better, you’d mix in some compost, too, as the carbon and the microorganisms should help make the minerals more available.

  8. Can you use grass clippings instead of leaves? If so, what difference would there be in not using leaves? Thank you!

    1. Grass clippings can more easily become anaerobic when piled on thickly, and piling on thickly is the goal here. If you don’t have leaves, a thin layer of grass clippings is better than nothing. If you do have leaves, you could mix in a small amount of grass clippings, maybe 25% or so. But I wouldn’t do a thick layer of grass clippings on their own.

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