Mulch or Compost?

by Daisy


Big crashing noises at 3:45 a.m. seldom bode well.  Ours is the house to the right, which you can just see if you squint real hard through the branches.

Fortunately, no one was hurt, and only very minimal damage was done to the house.  It did bring down the power line, so there was that, but since it was a cool, nice day, it was a very minor inconvenience.

The tree company showed up with their smallest crane.

It was huge.

It barely squeezed up the driveway.  They made such short work of that entire tree, we couldn’t believe it.  They had the most amazing chipper.  We stood, jaws dropped, as the workers directed limb after HUGE limb into that thing, and it acted like they were toothpicks.

As we watched, the entire tree, save for the very largest part of the trunk, was pulverized into small chunks.

And if you know me, you know what I was thinking: MULCHMULCHMULCHMULCH!!!!

Since the tree company has to pay about $100 to dump a load of wood chips, it didn’t take much convincing to get them to leave the contents of the chip truck in our yard.

Now I have a whole tree’s worth of wood chips in a pile, a mountain, in the yard.


Here’s the thing.  Look again at the mulch mountain and notice the steam coming off the mountain peak.


The tree was completely leafed out, so mixed in with a whole tree of fresh wood chips is a whole tree’s worth of fresh green leaves as well.

It’s a hot compost pile.

What do I do with it? Do I let it alone and let it compost?  How long would that take?  Do I go ahead and use it for mulch?

My first thought is to let it go ahead and go through a heat and cool cycle and see what’s going on in the center by then.  Then reevaluate.

If anyone has experience with this sort of thing, I’d love to hear your story.

Disclaimer: This post may contain a link to an affiliate.

{ 36 comments… read them below or add one }

Brad Dawkins May 27, 2013 at 6:37 am

I have a similar situation and would also be interested about how to think about this.

Lora Day May 27, 2013 at 7:39 am

I would let it work. Next year you will have great mulch for your garden. You can plant pumpkins on it this year to beautify it.

Decklap May 27, 2013 at 8:33 am

It will be broken down by beneficial micro organisms either way. It’s going to take a long time for that wood to compost fully. I’d use it as mulch

Cat May 27, 2013 at 8:55 am

I think if you have the space and you don’t need the mulch right away it would be interesting to let it go a cycle and then decide. Even if it does compost out on the inside you should still have a good amount of mulchable stuff on the outside.

Cinnamon Vogue May 27, 2013 at 9:18 am

I am thinking you would have to bury it with lots of water, soil and worms to make it into compost. Even then I guess about a good 2 years before you can use it as compost. Using it as mulch is a problem, because as wood chips decay they aborb lots of nitrogen, depriving nearby plants of all the nitrogen they need. So better bury it and also add 50% nitrogen rich material like leaves (which was already mixed in your case), grass clippings, kitchen waste and anything else you can find to dilute the wood chips.

Debbie May 27, 2013 at 12:00 pm

I know from working with a lot of Florida Nurserymen (I learnt by osmosis…(O:) to never use green wood chips as mulch. It will leach all the nitrogen out of the plants causing them to become weakened and susceptible to pests and disease. It’s best to let it set and age for about 9 months to a year (or depending on your local climate). I believe that potash will help break it down more quickly. Also the use of a rototiller will help to turn it.

Hopefully this will help you with your decision on what to do with all that good stuff.


Kat May 27, 2013 at 5:42 pm

We had a similar experience a few years ago…except it wasn’t our tree that came down. We knew the tree service guy with the magic munching machine and he gave us a load of mulch from a healthy tree (we didn’t want to bring some plant disease into our yard). After it was dumped, we did….nothing. Just let it sit. In our case it came in the fall and sat all winter. By springtime it had broken down into a beautiful compost, which we spread under the drip line of our trees to keep weeds from sprouting.

In addition to the fresh mulch causing problems with the nitrogen in the soil, I’d be very concerned about the heat it generates–couldn’t that damage the plants too?

Susan May 28, 2013 at 4:27 am Seriously! Best use of a mixed mulch like this.
Pick a permanent garden spot, Layer with several layers of newspaper, pile on the mixed mulch several inches thick. Never till the spot again. Leave the mulch on top of the soil.
Watch the film. It’s free to watch online.

Ecohomesteader May 28, 2013 at 5:36 am


If you get a chance, you must see a documentary called Back To Eden. It talks about this very type of mulch. Use it to cover your food bearing garden beds. It will reduce your weeding significantly and cover the soil preventing erosion of nutrients from exposure to the sun. Also, it will virtually eliminate your watering as the mulch holds water from rain like a sponge and will release it as required.

Once you have attained a thick enough bed of mulch (4-6″) you will never have to till your garden. To plant in the future just make a furrow in the mulch without disturbing the soil beneath, rake some mulch over the seeds you place in the furrow to cover and water until you see seedlings surfacing. Then you stop watering for the season. Your only garden tool will be a rake.

Happy Gardening,

Deborah May 28, 2013 at 6:01 am

I don’t advise using it for mulch right now. I needs to be composted first. I made that mistake one year using freshly cut tree waste to mulch my garden, and it killed almost everything.

Amanda May 28, 2013 at 8:40 am

Lovely! You’ve gotten plenty of comments so far but I want to add my vote to the let-it-sit crowd. Its too hot AND it will bind the nitrogen. Add your scraps to it and turn, turn, turn. Also be sure to WATER it down and keep an eye on it because fresh mulch like this can combust in the summer months if your area is hot.

Ecohomesteader May 28, 2013 at 9:12 am

I understand the idea of it being too hot, but if you spread out mulch into a thin layer, the heat is distributed. I don’t recommend the mulch for beds you already have plants growing, but in an undeveloped bed, you can start to begin your mulch bed for next year. The idea is to mimic a natural forest floor where you have leaf matter decomposing alongside fallen trees , etc.

As for the nitrogen binding, that is only when you have pure wood chips or sawdust. The greenery of the branch reduces that. When you watch the Back to Eden film (it is on You Tube), you will see how well this system works.

KimH May 28, 2013 at 10:00 am

I agree with those recommending the Back to Eden mulch method..
I’ve had experience several times with huge piles of wood chips like that. It is NOT going to compost in one season.. Aint no way, not gonna happen.

I’ve got a nice pile in my front yard that is finally this year, after maybe 6 years, where a huge pile has gotten to the point where I can actually plant in it. We had a tree stump chipped up into pieces like that. And that was mixed up with dirt too.
I also used to get the electric company to dump truck loads on my property in Texas and they took years to become compost other than for mulch. That is what it was best for.. mulch.

If you lay the wood chips on top of the soil, it wont bind up the nitrogen in the soil for your plants.. Its when you till it in that it starts binding the nitrogen. If you look at nature.. the branches & leaves fall on TOP on the soil… and then it easily rots and nature takes care of the breaking down and LOADS of new plants grow in the forests and planes where branches, grass, leaves etc etc have fallen & made a new layer on top. In nature, they arent mixed into the soil as would be with a tiller. Just layer it on top of the soil and let Nature take care of it wherever you’d like to have it. Just dont till it in or you will have a pile for years like I did.

If the Back to Eden videos irritate you (they do me, though I agree with the philosophy) then perhaps check out Ruth Stouts No Till Gardening.. She was the one who started this back in the early 1900s..
Her books can still be found at Amazon & probably Mother Earth News since they were a big proponent of hers when she was still living.. Our local library still has some of her books as well.

Lisa Mertins May 28, 2013 at 11:10 am

I’m a hot pile kinda gal 😉 so I envy you that steaming heap!

Do you have an existing compost pile? If so, I’d let this cool then heap it onto the one you have (or visa-versa!). That might be a lot of work so maybe you could rake the part that’s not breaking down right away on top of the steamy part (once it’s cool) so it will heat up again. Then the whole thing should start shrinking into beautiful soil.


gillian May 29, 2013 at 4:44 am

Not much help here, but we had the exact same thing happen 23 months ago and the pile still looks like mulch. (I haven’t been aerating it, or treating it like compost though.) I mulched my blueberries with it last fall and they are fine. I am using the rest of it as flower/vegetable/path mulch this month. Good luck!

Marilyn May 29, 2013 at 5:03 am

If you want to make a bed in fall for next spring – you weed the area, maybe put down newspaper or cardboard and soak it well, put down compost, then put down wood chips. You pull back the wood chips to seed/plant in and as the plants grow, push the wood chips back towards the plants to mulch. You side dress with blood meal or the equivalent. Back to Eden does use his chicken yard compost over the top for feeding – it leaches in when it rains. The movie is good – but most info comes from the not-so-well done you tube questions/answers from L2survive – We’ve proved it works before we tried it and you can also turn that pile a lot and make it compost faster. Just my 2 cents

karen May 29, 2013 at 5:25 am

Depending on the type of tree, which in this photo looks like an Oak, DO NOT USE IT AGAINST THE FOUNDATION OF YOUR HOUSE! You are not the only one who finds that steaming pile attractive! It is an invitation to all termites to come to the feast! Pine bark is typically used as mulch and is not an issue but oak is a disaster waiting to happen. I have done this for years with a local tree company and have used the mulch around my yard – skimming off the top layers that are not steaming – and allowing them to break down in the gardens. Oaks are very acidic so I toss in a bit of lime as well to neutralize it all. The plants seemed to love it and it kept away the weeds. My yard smelled great for weeks too!

Chris May 29, 2013 at 5:33 am

Let it be. Turn it regularly. That is the process that kills off growth of weeds, plant sprouts, etc. It is the curing process in making mulch. The county I live in has a mulch site (I used to work there). They chip up vegetation like that and place it in rows. It is turned regularly. It takes about three months to cure it so mulch can reduce weeds rather than generate new vegetation.

Cynthia May 29, 2013 at 6:44 am

What a beautiful old tree – hate to lose those! Sure u will miss that. Interesting comments. I always flag down the tree service trucks and they gladly give me as much mulch as I want. I put down 3 inches of newspaper and then mulch on top of that. Use it around asparagus, peonies, and flower beds. Works better for me than the black fiber used for weed control.

Debbie May 29, 2013 at 7:13 am

Another thought that was triggered by another commenter is this…if you’re concerned about insects, Neem oil is great for controlling those. It’s extremely safe to use. And, I also agree that if your area gets hot in the summer, be alert to your pile catching fire. Here in our area is a dump that was mainly for tree service, lawn service, construction debris, etc…but not food products, that thing got so hot it caught on fire and I have no idea how long it burned.

Just a couple of thoughts,


Handful May 29, 2013 at 7:43 am

Lucky you! My late husband and I owned and operated a tree service so anyone that wanted chips could have them for sure! Definitely let them sit for one full year before using or it will suck the nitrogen right out of the soil and any existing plants. You can turn it to help it break down more rapidly. It will turn into compost eventually but I would use it as mulch and let it break down the rest of the way there. By the way, strawberries LOVE wood chips. Use them next year on your berries.

Nancy May 29, 2013 at 8:05 am

Put this word into your browser and have fun discovering how to use these wonderful wood chips. You will be so happy you did. I also recommend “Back
to Eden” film.
Best to you and your garden.

mjs May 29, 2013 at 8:14 am

If you bury chips in a hole a couple of feet deep and cover with dirt, you would have a raised hot bed to grow a fall/winter garden.

Ronda Wintheiser May 29, 2013 at 9:09 am

I’ve recently begun a straw bale garden, and in researching how to do it, I read that it takes several years for wood chips to decompose enough to use as mulch.

You might explore the book I’m reading — STRAW BALE GARDENS by Joel Karsten.

Naomi May 29, 2013 at 9:40 am

I would say use it. I volunteer at a community farm once a week and the one of the main guys works for a landscaper and they come and dump load after load. It goes straight on the farm. It is going to decompose anyway so you might as well get the benefits now rather than wait and lose some of it

Julie Carmen May 29, 2013 at 9:40 am

We did the same thing with our dead Juniper bushes. We built a compost box with old wooden slats and put all of the chips there and we use it for mulch only. However, after a year, the mulch has become compost so we stir it up with some food for the plants, and the worms love it. Then we top off with more of the mulch. By the time we get to the bottom of our 6 ft by 4 ft box, we will have compost.

Jeanie May 29, 2013 at 11:29 am

That’s pretty hot. It reminded me of experience as a childplaying on a large pile of sawdust in a recently harvested woodland and digging into the pile and finding evidence of charing and increasing heat. Sawdust piles, left alone, can spontaneously combust. The heat builds gradually, but you might want to do some compost turning before the core gets so hot that it flares when suddenly introduced to air.

Jason May 29, 2013 at 11:30 am

I would spread it as mulch as originally planned. It will still slowly decompose over time.

Sara May 30, 2013 at 7:10 am

We recieved a delivery of this type of mulch before. We went ahead and used it right away and it did beautifully. We were sure happy to get a big free pile of mulch!

Christine Lampe May 30, 2013 at 8:03 am

I posted your question at the Dirt Doctor’s facebook page and here is his answer:

It can be used right away as a top dressing mulch. Just don’t mix it into the soil until it has composted down – which doesn’t take long because of the good mix of carbon and nitrogen in the material. Recently living tree trimmings contain cellulose in the wood and protein in the buds, cambium and leaves.

sissybear May 30, 2013 at 11:48 am

How about half mulch and half compost? Now is a good time to examine your other trees to see that none of their branches are at too narrow an angle to the trunk or if any other catastrophes are waiting to happen. Shame about that nice tree. What was the matter with it?

Daisy May 30, 2013 at 12:17 pm

sissybear–We had many of them trimmed for that very reason last year. They are all getting to be that age. That tree, a hackberry tree, seemed to have some rot at a fork and had lost a large limb on the other side several months ago. It looked ok, but obviously it wasn’t.

Daisy May 30, 2013 at 12:20 pm

Christine Lampe–Thanks for doing that! I like that answer, as well!

Vonnie May 30, 2013 at 6:01 pm

Our neighbor had a huge pine/fir tree taken down last fall and we immediately requested the chips. We used it for mulch immediately under trees and other areas we wanted to keep weeds down. yes it was steaming almost immediately, no it didn’t burn any of our trees and bushes. I think it was the thin layer as opposed to a full 4-6 inches.

Dawn @ Small Footprint Family May 30, 2013 at 11:35 pm

Green, freshly chipped wood is a bad mulch unless you are using it on paths. It will steal the nitrogen from crops otherwise.

However, you do have to be aware of fire. I’m not sure how tall/wide that pile is, but large, composting wood chip piles are known to combust in hot, dry weather, so if you compost it, keep it wet with the garden hose during the summer.

jo May 31, 2013 at 6:59 am

It needs to finish composting-otherwise it will kill any plants you put it around, by taking the nitrogen and adding all that heat you see rising . (If you have an area, say, around a fence post,ect, that you want to die, put it there and it will do the job for you) Keep in mind that carpenter ants love this stuff-avoid using too close to your home/garage. Any mulch can also draw termites. If it is a black walnut mulch, the oils will poison most growing plants for a long time. It would be good as a border around your garden edges, away from plantings, to keep weeds at bay as it is composting to a non-green mulch. Give it a year if undisturbed.

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