This latest mulching technique that is detrimental to trees has been nicknamed “Volcano Mulching” for good reason.
I’m not sure where or how this started but it is destroying trees in landscapes across America. Probably beyond our borders as well, but I don’t know for sure about that.
Take a look at these two photos.
Notice how high the mulch is around the trunk of this tree. That is not good. All plants, trees, and shrubs have a root crown. That’s the point where the roots stop and the upper part of the plant begins.
Roots need to be covered with soil at all times and not exposed to air. Roots know how to deal with moisture and are designed to absorb moisture to provide nutrition to the plant.
The stem of trees and shrubs should not be subjected to the same kind of moisture. It will damage the stem of the plant.
The two photos that I am showing you here have way too much mulch around the stem of the trees. In other words, the mulch is too deep. Actually, these two trees are mildly over mulched compared to many that I’ve seen.
When you pile the mulch up around the stem of the tree the excessive moisture that the mulch traps will begin to decay the bark of the tree.
Pretty soon the bark will begin to pull away from the tree, exposing the cambium layer to the air, and allowing insects, disease, and fungi to go to work between the bark of the tree and the tree itself. Eventually, the tree can die.
It’s important to understand that right below the outer layer of bark is a layer of tissue known as the cambium layer.
The cambium layer is the circulatory system of the tree. All of the moisture and nutrition that feed the tree travel through that cambium layer. That’s why it is so important to protect the cambium layer.
When you plant a tree or shrub you should never plant it so anything except the root crown is covered with soil. In most cases I suggest people install plants so the root crown is at least one inch above grade, then covered with soil and a light layer of mulch.
No more than two to three inches of mulch and even that should be pulled away from the trunk of the tree so there is air flow between the mulch and the trunk of the tree.
Where and how this volcano mulching thing started I have no idea. I first started working in the landscape trade when I was 18 years old, that was almost 40 years ago, and we never did this volcano mulching thing, nor did anybody else.
But then a few years ago I started seeing these huge piles of mulch around the base of trees in parking lots etc. Then unknowing homeowners see this practice and start repeating it at home.
You’d think that people in the industry, meaning the landscape contractors that take care of these commercial properties, would know better.
I’m sure most of them do, but it’s the few that seemed to have started a trend that truly needs to be reversed. Believe me, I’m not the only one on this bandwagon.
Be kind to your trees.
This has bothered me for years! Very few Landscapers listen…much easier and faster for them to zip around on their huge stinky mowers. I thought the tree flare was the reason for NOT burying the trunk so deep. When you see a Wild Tree…it will always flare out at its base…. A friend did a test where 2 trees were planted one properly, depth and flare exposed, the other right depth but flare covered by mulch. The size and health of the tree with flare was almost double!
IF YOU CARE…SHOW THE FLARE
I always thought that a tree will send out roots at the new base of a tree to hold itself up because after all, it thinks it’s the ground. Then the deeper roots that are really holding it up will die because all the love is going to the new roots. the new roots aren’t strong enough to hold up the tree and it dies or falls over.
No, that soil or mulch will rot the bark of the tree and cambium layer is damaged and the tree dies.
Hey Mike. What do you use for mulch around trees. Thanks
RJ
Bob,
Double or triple ground hardwood bark mulch or dyed mulch lasts longer.
Can’t believe people who should know better are STILL doing this type of mulching. I learned how detrimental it was nearly 50 years ago in Master Gardening class, plus in Landscaping class.
I think some people are seeing mound planting and mistake it for mulch. Here in our part of California the soil is so hard ( mostly clay ) that growers mound up the soil above the clay and spread the root system ( bare root ) to give the tree a chance to grow. The tree will eventually send roots down into the clay soils. The best root stock, for fruit trees, is Citation. It is for growing in clay soils.
If you see orchards mounded like this it is not mulch but mounded soil.
Regardless, getting soil/mulch this close around the trunk base is generally not a good practice.
Have to remind myself , each time planting trees/shrubs, not to make this common mistake.
Yes Mike they got it wrong and I don’t know where they learned to do this. This is great for the tree but they need to spread it out with a six foot circle around the tree and move the mulch back away from the tree 4-6 inches. The base of the tree needs to get air. It is a great way to feed your tree and it keep the moisture in the ground and from drying out in very hot climates like we have out west. It keeps the soil much cooler under the mulch too and doesn’t burn the tree up especially in the desert . Plus it keeps weeds from growing around the trees. After the first year you would be surprised how many worms are under the mulch or wood-chips.
Hello Mike, a couple of questions. I do use a lot of mulch around my trees but I’ve always been told to never cover the trunk of the tree for all the reasons you’ve mentioned and to get Air. So after I mulch I pull it back from the trunk. I use black mulch . Can this mulch cause a fungus (?) on the trees? I have this light green looking fungus (?) and it grows from the ground all up through the trees. What do I use to kill it. I have two apple trees that I’ve had for about 5 years . One had about 4 apples on it when I bought it and they were delicious. But since then nothing. We get tons of blooms . And then we get a frost . I always cover them but it doesn’t help the blooms fall off. What do you suggest I do for both problems. Is it a mulch problem? Some places if I lift up the mulch there is a white looking fungus growing in the mulch.
Donald,
As long as you don’t have the mulch up on the stem of the tree it shouldn’t be a problem. The white fungus in the mulch is pretty much normal from rotting wood. I think the issue with your apple trees is not related and I’m not sure what the problem is.
It might be a mineral deficiency. Have you had any soil tests done?
Hey Donald, I live in the high mountains of the SW at about 7000 feet. Our last frost date is May 31. Yes, the 31st. We can have a blossom killing freeze up till then. My wife and I have spent endless hours on the internet looking up fruit trees and berries that can tolerate our climate, short growing season, and the very cold winters. We had to find apples, that are late bloomers, honey berries that are late bloomers, grapes that will survive our coldest winters (-27 F) with out top kill etc. We have been trialing two varieties of peaches, contender and true gold, and manage to beat the frosts about once every 3 to 5 years. When you search sites look for ‘late bloomers’. Ag.edu web sites have good info, too. best of luck.
There were some questions about the correct shape of the mulch around the tree. Mike said he would try to do a video, but I don’t know if he has, yet.
Imagine the top half or third of a bagel or doughnut around the base of the tree. The mulch should be the same shape – sloping down toward the trunk, with a small amount of the soil exposed (presuming the tree was planted at the correct depth.
Thanks Bruce, that’s a good description of how to mulch around trees.
I haven’t encountered this (yet) in my part of Northern Ca, but not only is it bad practice, it looks incredibly dumb and unnatural! Where in nature do you see this sort of thing going on? Does a forest volcano mulch itself? We should all exercise a little humility and respect, and take our cues from Nature’s lessons. This is why I enjoy your work, Mike – because you know how to align with the natural world, and teach us how to really CARE for our plants and our landscape rather than looking trendy.
Sage,
I agree with you, I often tell people that the plants know what to do. We don’t need to micro manage them. We need to leave them alone and they perform perfectly. Always think about how it happens naturally. That’s exactly what plants need.
We do something almost as crazy in CA. People let their sprinklers hit the tree trunks. Some trunks do ok but many end up dying because the water hitting the exact same spot everyday (it doesn’t rain in the summer) erodes the cambium lawyer. It makes me nuts. Coast redwoods die from this all the time in Bakersfield where live.
I live on a 5 acre wood lot next to a Conservation area in rural northern Illinois. It’s extremely difficult to reforest former croplands to hardwoods such as oaks, hickory, hard maple, elm & ash. In picnic areas, the Conservation people mulch the trees so it is easier to mow and maintain, but they are mulched flat. I prefer to let autumn leaves do my mulching as I have enough to do to try to prevent rodents from girdling and deer from eating or scraping young trees.
I see this all over Georgia with the pine mulch. Pine needles draw ants, and they love moisture, good bye trees.
Is it okay to use gray river rock around the base of a tree? It’s in are front yard and we did this because we like the look. And when we use are blower the rocks stay in place!!
Greg,
Don’t push them up on the tree, they really shouldn’t touch the trunk of the tree.
I’ve read about 1/3 of these comments, I stopped when a couple people said that Mike was dead wrong about Volcano mulching. I volunteer at an extension office that has a master gardener program. I have witnessed firsthand what volcano mulching can do. We lost a beautiful mature dogwood because the bark at the base had rotted from the mulch. I do believe however some trees are more susceptible to damage than others. Mulch textures could also play a role in it, the chunkier than mulch the more possible air could circulate through. I do not mulch above the flare of the tree, I believe the flares are beautiful and unique for each tree.
Erin,
You are right and I’ve seen where even very coarse mulch can hold too much moisture against the bark of a tree.
Good advice about mulching. Another issue is young trees in cold climates need the lower part of the tree either painted white or a tree wrapped used to protect the tree from defrost and refreezing which can kill the tree on one side
Can you please help me understand , how painting lower part of young trees’ trunk white protects ftom freezing?
I thought painting white protects from sunburn.
Scotty,
I don’t think the white paint is to keep them from freezing but to actually protect the stem of the tree from the sun at all times of the year.
Mike,
I’ve read most of these comments and I guess I’m one of the monkeys ashamed of piling mulch.. Haven’t killed the maples yet but root systems have grown up above ground some 8-10 inches. My question is do I trim all these roots back down to the ground and put two inches of mulch over that. The trees look ugly now at the base but they’re healthy and I don’t want to kill them.
Tim
Tim,
Probably just a light layer of mulch to cover the roots with almost no mulch against the tree itself.
Mike, recently I have read about using flattened cardboard boxes under a layer of mulch for weed prevention. Is there a risk of the cardboard “smothering” tree roots? I believe the cardboard will deteriorate over time but in the meantime will it let moisture get to the soil?
Jane,
I think the cardboard is harmless, just don’t put it against the trunk of the tree.
Show us how to do it right!
Irene, I will. I’ll do a video but remind me if you don’t see it soon because there’s a lot rattling around in this old head of mine. Basically 3″ of mulch and not right against the bark of the tree is ideal, but there more about tree planting that I need to cover.
Put some raised flower beds around a couple of oak trees two years ago with about 6 inches of soil up against the tree, think it’ll be ok?
Mike,
For this is not a good practice. Will it harm your trees? It could.
We have tree roots protruding from the ground either by growing out or by soil being washing away–or both. Should we be covering them with soil? Thank you!
Evelyn,
You can cover them with soil but chances are the tree will be just fine if you don’t. Some trees, lots of maples, tend to do this.
While working in the park dept. we became aware of this problem even before the trees were planted in the various parks. At the tree nurseries where we purchased the trees & shrubs we noticed that the root flares were buried anywhere from 1 to 6 inches. We also noticed that in many cases the roots started growing around the main trunk which would eventually strangle the tree. Please check the depth of the root flare and expose it even before you plant the trees.
After implementing this into our planting & maintenance program our success rate definitely improved.
Great information, thanks Dennis!
I noticed at a mall where they had rocks piled up around the trunk and I told some of them they were about to lose thousands of $$$$ before too long.So you know men, they weren’t going to listen to any woman. Sure enough they lost every tree on the new mall sight! What is wrong with people anyway? They should know trees have to have oxygen too. Enjoy your comments. Thanks. Cleo Hales
Cleo,
For years and years I’ve seen it all, trees being planted too deep, trees being planted in wet soggy ground. All certain death for trees.
I ;lived in Houston for 7 years and this is quite common to see. Because of flooding there they plant many things slightly above ground to help prevent water logging the roots. That is what I was told when I asked before. Originally from the Midwest, I have not seen this until I moved south
This is only what I was told by our groundskeeper at the apartment complex we lived in years ago.
Rusty,
Planting something high is fine as long as it only has 3″ of mulch over the root ball. But this problem is trees planted at normal depth then mulched too deep.
In parts of California the ground is heavy clay so the farmers mound up the soil, you can see Dow and rows of mounds, then plant fruit and nut trees on these mounds. But they then will push soil over the spread roots just enough to cover them. So as they say Monkey see, Monkey do. Or if it is good for the goose it is good for the gander. Never knowing the whyfor.
Scott,
Building a mound then planting the tree in that mound is fine, then putting a couple of inches over that is fine. But when the tree is planted at grade, then soil or mulch piled up around the trunk of the tree is when the problem comes in. Raised beds are really only necessary when the soil is so poor, or so wet, that the tree would never survive planted at grade.
I learned this the hard way. After years of planting trees that I visit, I know maybe a little different but I take cuttings from them and propagate but all another story. I planted a peach tree in my yard a few years ago, I followed all of what I thought the rules were. I dug the hole twice the size and depth of the ball and there was the mistake. When I planted it the ball was at level but I always backfill to grade the tree with organic materials and over the last few years they broke down and I continued to mulch. The tree sank below grade and I hadn’t even noticed but I knew it was not growing as it should. This spring I did a water change on a fish tank and poured the water down the trunk and it washed back the mulch and I saw a gaping hole almost half the tree eaten away. I dug out until I hit the highest root and have kept everything pulled back in hopes the tree survives and low and behold the tree has its first fruit since the year I purchased it.
This is done by the many hispanic yard mowers who think they are landscapers. I dont know why or when started, but know home owners repeat this dumb mistake.
Seems like a racist comment to me. Landscapers come in all sorts of sizes, shapes and colors and I think the problem we are addressing here is across the board. Some of the best landscapers I know are Hispanic.
Hi Mike
Greetings from Finland, the land of the Santa Claus and the Sauna and the Nokia.
Thank You for all of the good information You are giving us all.
You are 100 % right about the damage of Volcano mulching.
I think people have mixed together different metods without thinking about the damage this modern mix causes to the trees.
We have very cold temperatures in Finland ( Winter temperature record -52°C ( – 62F)) and high mulching bed for apple trees has been done to rise the temperature in the ground around the apple tree roots.
But the apple tree in a mulching bed must always be planted higher up so that only the roots are covered, never ever the stem.
I think people are using this volcano mulching only because they see it all around the parks and it looks good. They are not aware that the tree may die.
Tom Eklund
Finland
You’re right Tom, it’s monkey see, monkey do.
I have a similar problem with one of my peach trees, except it’s with plastic tubing,down o the ground.
We had a very hard winter,followed by a late,wet spring.
It’s not leafing out,and is weeping at the root joint.
Is it a loss?
Faye,
If it hasn’t leafed out by now I’d consider it a loss.
Hi Mike,
I know this original article is a few years old now, but people still need info on mulching – why to mulch., what to mulch with, and how to mulc (how deep, not covering plant crowns, lossen up old mulch first, etc.)
We like mulching with composted leaves (leaf mould), and many of our plants are close enough together (as mature plants that weeds are mostly shaded out and not a big problem. We’re not fond of big open areas of mulch in a mature landscapte. Or, worse yet, the dyed wood mulch. We prefer living groundcovers and mulches that feed the soil and the plants.
So yes, please, do another article – or add to this one – with more info about mulching!
Okay Ann.
I have watched landscapers at the place i work do this. I noticed they come in and edge each tree flipping the dirt towards the inner circle and leaving most òf it there. It gets smashed down a little bit and then a thin layer of mulch gets put over it. As the grounds keeper I have had to dig to pull out the weeds and found more dirt than mulch in that big mound. I guess the less dirt they have to pick up in their wheelbarrow and place in their truck is time mgt. on their part. Our hired landscaper teams stay away from heaping up of dirt and mulch directly against the bark and there is a low hollow area about 6-8 inches out from the tree. Would this still be bad for the trees ?
Sherree,
It’s probably fine. Eventually those clumps of soil and sod break down and pretty much end up right back where they started.
Hi Mike,
Volcano mulching has been going on for at least 15 years here in Vermont. I can’t tell you how many times I’ve troweled out a breathing space to stop the potential damage to the tree. Some of these piles are well over a foot deep. Worse yet, you can be risking your life if you try to explain to the home owner that their (overpriced) beloved landscaper needs a few more hours in the classroom.
Yeah, Daryle, I agree with that.
Who goes into the woods and clears out little 1 inch circles around the tree trunks?..No one and they all do perfectly fine.
You really should watch Back to Eden film and see that Paul has mulch around all of his orchard trees 16 inches deep and has for many, many years with no problems.
Use common sense folks, no one cleans little air pockets out around any trees in nature and they do just great.
Yes, I agree that you should see the back to Eden documentery.
There are also many dozens of youtube videos of Paul Gautchi giving garden tours of his amazing fruit orchard and vegetable and fruit garden using wood chips and chicken made compost, no fertilizing, NO WATERING.
The easiest way to find the BACK TO EDEN documentery is to do a youtube search for VOLVER A EDEN, which has been subtitled in Spanish, but the audio is the original English.
Paul is an amazing person, very much an inspiration.
YOU ARE DEAD WRONG ON THIS POINT Mike
Ron,
I am not dead wrong about piling mulch up on the stems of trees. It can and will kill them.
Paul’s apple and stone fruit, and who knows what else, have had 1`6″ deep wood chip mulching right up to his tree trunks for over 37 years, the trees produce fruit abundantly and other consequences of the mulching, in an area that gets 14 ” of rain a year
He never waters his trees
he never fertilizes his trees
He has to give away the fruit
The water content of his fruit are fare sweeter and more water content.
Ron,
If that’s a chance that a person is willing to take with an expensive tree that is a valuable asset to their landscape that’s their choice. But I’m not the only person to bring up the topic of volcano mulching, it’s often discussed by universities and experts across the country. And of course the type of mulch matters but I honestly don’t ever see the benefit.
As an arborist… mulch or especially soil above the roots line, on the trunk of a tree will kill it, period. Might take longer in desert conditions. Amazing how you give correct advise in an attempt to help people and they still argue with you.
it is not around the trunk of the tree, but over the roots, like in the woods where trees mulch themselves with leaves (instead of removing them) The root flare prevents the natural mulch from contacting the tree trunk. Maybe missed that part?
Hi Mike, Everyone,
I guess I’ve grown out of my cynicism and don’t believe ‘landscapers’ do this on purpose to make $ on replacement. I believe that there are different roads to this Dead End. The main culprit is lack of training for seasonal labor by the ‘professional landscaper’ (or mow, blow & go outfits). That is if the ‘professionals’ have ever even had the proper training. I tell people it’s no harder to do it right and it’s not that hard to learn how!
Even a simple switch from volcano to caldera can be helpful! Caldera posse anyone? Meet me at McDonald’s!
That said, I believe the bigger crime is how nursery stock is sold. Every time a client insists on a tree of 1″ caliper or up I make sure to expose the root flare before planting. Anybody else had the experience of removing 4-5″ of ‘soil’ before finding the flare? It seems 1-2″ of excess soil is being piled on the roots each time a tree is potted up! A very good way to start tree roots girdling! Then the poor things are planted too deep in the landscape and over mulched (over and over) by the untrained crews. It seems to me, more often than not, the death knell for the tree rang long before that mulch volcano was created.
PLEASE!
Expose those root flares and remember if it looks like a telephone pole…it’s planted too deep.
While I’m here may I remind everyone that not all plant ‘pests’ need to be eradicated. Insects are an important part of our food chain and some rely on our plants for their food so they might possibly become a tasty morsel for another hungry critter and so on.
Plant more natives and rejoice in those nibbled leaves!
Good information Kevin, thanks for sharing.
Thank you. Systemic pesticides should be banned. Does anyone remember our Bald Eagles and DDT? Learn from past mistakes.
I have known Volcano mulching to harm or even kill trees long ago. you must leave 1” space between mulch and base of tree. you can buy tree sleeve protectors off internet. just make sure you don’t go over the top of sleeve with mulch. If you want to Volcano much make sure you use the sleeve protectors. extra deep mulch will help protect in very dry summers, just do it right. I like the Mexican people but, in our area they are the ones for hire that are big on Volcano Mulching. If someone would introduce them to the sleeves this would work. Hope this has not been taking the wrong way.. THANKS CARL
Hi Mike. I haven’t see any of the volcano mulching in Phoenix, but now I will really be watching for it. I doubt if it can/will be done here. I believe the reason being is it’s so HOT and DRY. Deep watering is a necessity! The top would dry out so fast, the water wouldn’t have time to get to the roots! I don’t understand since you get (mid west and east) so much rain why you would want to pile mulch up and rot the bark. People use drip irrigation systems for their trees, but I prefer using deep, large wells. More maintenance, so you don’t build up dirt/mulch around the trees. Plus, I love spending time with my trees and shrubs. 🙂 I don’t have any Arizona desert trees. I like ones that are a challenge to grow here. Thanks for sharing your knowledge.
P S : I am also sending your article to Local, State and Federal government offices. Thanks again.
Thanks SO much, Mike = I’ve been extremely upset by this volcano mulching practice. I’ve been looking for a knowledgeable resource to get this message out and convince others. Your article is perfect.
I think this style of mulching has been promoted by landscapers: (#1) to make the property look neater, but mostly (#2) it saves them time trimming between the “toes” of the tree (especially landscapers of commercial properties.).
I hope you don’t mind, I have printed several copies of this article (with your name and website on the heading) and I am posting it at the library (hopefully all of our library branches), grocery stores, laundromats, gas stations, business offices, and anywhere I can.
Healthy trees are SO critical to our environment. If homeowners, businesses are burdened with the cost of having their dead trees cut down and hauled away, plus pay for the cost of a new tree .. and .. the labor cost of planting a new tree, they may eventually decide to do without trees, and trees do so much more for us than to adorn our property. Trees are crucial to our health and environment. Keep up your GREAT work. God Bless You for all you do.
Thanks Deanna,
You’re welcome.
I tried to share this but your “underground video chatroom” image pops up as the image and not what the story is about. Make your first image of the tree and mulch and move your video to the end if you want people to share and get the message out there..
I think your story is great.
Bill,
You should be able to close that pop up window. As annoying as they are, they are necessary to get people on our mailing list. That’s how we support all of the free content that we provide.
Pretty informative and on the point as always. Many thanks Mike for your articles.
A landscaper who planted a tree for me a few years ago said that the mulch around a tree should look like a doughnut, and demonstrated by applying the mulch in like manner. She said exactly what you’re saying–that the mulch should not be mounded up like a volcano!
HI Mike, Here in Minnesota I have a lot of black walnut trees that I have had to cut down because they were over taking my garden space. I know the tannic acid from the roots and even rainwater dripping off the trees kills the garden plants, so my question is, would the mulch from these trees also kill the plants that the mulch is spread on? Seems likely, but had to ask. Also, is there any toxicity in using the trees for burning wood in my fireplace?
Cheri,
Honestly I don’t know. I suspect if the mulch were allowed to age it would fine but I can’t say for sure.
Hi Mike
Thank you so much for your nice and helpful website!
i have problem with soft wood trees for Rot!
may you help me ?
i want to know how to make organic wood-hardener or chemical wood-hardener at home!
please help me!
thank you
and
best regards.
Iman
Not only is over mulching a problem but burrying the tree too deep
Many landscapers start out just mowing lawns
Then a homeowner asks them to plant a tree,they arent going to turn down money, so they uneducatedly slam the tree into the ground
You are absolutely right about that. Lots of people plant trees too deep. I need to address that and soon! Thank you for bringing this up.
Yes! They’re trees, not tomatoes!
Really late comment here, but thought I’d add my hunch. I think a lot of landscapers know that mulching plants like this dramatically increases their mortality rate. I also think a lot of them know that the vast majority of their customers don’t know that. While I’m sure many engage in this practice out of incompetence, I’m sure a great many landscapers do it because it’s profitable and they can get away with it.
From a landscaper’s perspective, there’s a lot of money to be made in killing their customers’ plants with mulch, because every step, from over-mulching to the plants’ eventual demise, represents an opportunity to sell the unwitting customer another service. What makes killing plants with mulch so great for them is that, sort of like the AIDS virus, it almost never kills directly or quickly. Death by mulch is slow, and the immediate cause of death will almost always be something else. People who aren’t paying close attention over long periods of time will never link the underlying cause and effect.
Landscapers make money selling services. The more they can sell, the more money they make. Getting you to pay for more mulch than you need makes landscapers money. When your plants’ health starts declining, and they start getting infections and infestations of one kind or another, or start suffering from drought stress, landscapers make money selling you spraying services to treat the symptoms of the underlying problem they’re not going to tell you they created. Then, when your plants finally die after years of declining health from something indirectly caused by over-mulching, landscapers can really cash in. Once your plant is dead, they make money selling you removal services, and still more money selling you replacement plants (usually cheap, short lived ones with lots of health problems, like Bradford Pears, which they get at wholesale prices and sell to you at retail). Finally, they make even more money selling you an assortment of other unnecessary, typically plant-damaging accessories, like plastic tubing, watering bags and guy wires, along with the next mulch volcano to get the revenue-generating cycle of throughput started all over again.
Andrew,
I’m not sure, I think it’s more monkey see, monkey do and they just don’t know any better. At least those that practice these kinds of mulching habits.
Even a monkey can see when his revenue and profits increases.
I have personally seen the scenario I described above play out several times. To give one example, along a street near my house, there are 30 year red oak trees with literally yardstick-high mulch volcanoes at their bases. The landscaper, who is hired by the township, has been told by a number of people that this practice kills, and has killed a number of, trees, but every year he comes by and dumps more mulch on them. His efforts are paying off. There are three big trees that are going to need to come down either this year or the next, and it’s he and his crews that will be removing and replacing them.
He probably don’t care about the tree’s. He is probably looking at how much more money he will make. The mulch he puts on them now is double or even triple the amount of money if the tree’s die ,, then tree removal,, then plant more trees and it starts over.. I know it’s 2016 now I hope thing’s are better.
In most, but not all, cases you’re right, Barbara. I have talked to some of the landscapers that are taking care of the grounds for our hospital. (The only thing they are doing right is mowing the lawn!!) But back to the topic, I said to one of the workers that the mulch he was applying was too deep and that was why the evergreen hedge plants were dying. He said, “I know, but that is what the boss told him to do.” And, yes, every year they are replacing a hedge plant that has completely died out.
Andrew, deliver this article to the Township. Supervisor or Mayor.. taxpayers getting scammed.
If this is the case then someone should be taking this to the city counsel with the evidence to back it up like from Mike. At least that way the counsel can make a choice on the city landscaper.
Its about being part of the solution and part of the problem. I myself have gone to members of the counsel and even the mayor and voiced things I felt was wrong.
My husband works for a large landscaping company and I am torn on this one. He over mulches in that he adds a thin layer around our trees yearly without scrapping the old away. He is the one who they used to have go replace trees that died for whatever reason. His trees, ones planted by him where he talked to the owner normally live.(He drives by even years later to check on the ones in our locality.) The problem I have is he refuses to believe that those who taught him in this business were landscaping for large corporations who often had them change many fill in plants out seasonally so the mulching was only for looks not conservation. He is a 64 year old “Mexican” guy so I don’t see him changing anytime soon.
If you get that video out maybe I can show him how it should be done and why
Debbie,
I’ve worked with and around a lot of Mexican guys over the years and most are really good at what they do and have hands on knowledge. I think we all do “mulch overs”. My wife and I will loosen the mulch at our house one year then re-mulch the following. The issue with this post is 12″ of mulch piled up against the trunk of the tree. I will do a follow up to this.
Gee that`s how a dentist works too !!
what if there is no mulch involved, only built up dirt ?
I have hugh old trees in my back yard. Recently we built about 5 foot around with landscaping timbers and filled it with dirt..
will rot happen?
Jean,
Yes it will if you have soil up over the root crown. On trees there is a fine line between what part is supposed to be covered with soil and what should never be covered with soil.
That is something done in cities to plant annuals around street trees. It’s supposed to keep people from throwing trash . It involves rotating annuals so it can be lucrative. I think it and volcano mulching might also be anice attempt to keep dog urine off.
Hi Mike, I bought a house 12 years ago that has some mature Doug Firs at the back of the yard which were “landscaped” before I came here by adding dirt on top of rocks and cement chunks., raising the “ground level’ I’m concerned because the bases of the firs are probably about `10-15” below this. Should I take out all the landscaping to expose the flares on these trees? Obviously these ‘landscapers were going to plant around the base of the trees but never got around to it. Should I deconstruct this ‘landscaping’? Thank you!
Elizabeth,
If the soil is up on the stem of the trees, then it should be removed. If not, it might be okay.
You bet it will! And with soil it will happen even faster. The mulch will let a little (not much) air seep in. The soil wont.
They do it everywhere here in Virginia. Monkey see, monkey do. Landscapers profit from the difference between what they purchase mulch wholesale and charge the client.
Hi Mike! Thank you for all of your wonderful information. I really look forward to your emails. As for the volcano mulching, I have seen a lot of this. One problem in trying to correct this is that once it has been done under a maple tree, the roots rise up to get water and make a fibrous mat. It’s about impossible to rake away the extra mulch to start over and give it a nice little coat. The landscape guys just pile it on over the mat, making things worse for the next year. Also, on trees in the park strip, they seldom increase the size of the circle, so you have this little circle with a huge pile of mulch within it. I hate to think of what is happening to the root system as they are cutting the new circle!
Correction – I didn’t actually mean that the existing roots rise up. The tree forms a whole network of new little fibrous roots near the top of the mulch to get to the water that usually can’t get down through the crust! They never break up the old mulch, so the water just runs right off.
The cynic in me thinks that maybe some of the tree suppliers/planters know the trees/shrubs will eventually die from this and need to be replaced. As a note, some plants, like tomatoes, can actually benefit from being planted deeper since they develop new roots where the stem is in contact with the soil. This applies particularly to older seedlings.
Sure, Eric. But there is a big difference between an herbaceous plant, like a tomato, and a tree!
Oh Mike.. I can’t tell you how many ” so-called ” Pro Landscapers ” I’ve seen doing this around here.” You know People who have large trucks or even Trailers with so & so Lanscaping go buy after leaving a site.
Then you see what they actualy did & somebody paid them too. I just walk by and think to myself ..there’s another landscaper that kills his own work.
Then he’s off to his next job. I want to scream NOOOO!! Please you are killing rare trees , specimen trees. NOOOO! Sincerely Charles W.
Dear mike I like your blog and find it very handy. I have a question What about thoes old shreded tires made into a ring to keep grass from growing around the tree trunks. They cost about $20.00 and do keep the grass from growing. Are they dangerous for a tree. Such as your valcano mulching? Thanks
Al, I don’t honestly know, hard to picture. But I wouldn’t use anything around a tree to keep grass from growing. Especially anything that is not bio-degradable. Removing the grass, putting down newspaper or paper bags then mulching works pretty good. Nothing is really all that permanent.
How do I kill mimosas? I had one that I cut down that is close to my vegetable garden and I cannot kill the roots. Someone suggested black plastic. Maybe cover black plastic with very deep mulch?
Think organic. Tire contain chemicals and about 5-10 gallons of petroleum.
Good point, Greg! And even if people don’t ever plant to grow food in that spot, things could change in the future.
Here in my town they like to put retaining walls filled with dirt around trees. You can drive around and see what’s left of the tree!! A trunk, and the funky landscape timbers filled with dirt that smothered the tree. JEEZ!!
So show a picture of how you do it right.
Gordon, I need to remember to get that photo, but the easy short answer is about 3″ of mulch with about 1″ of air space around the base of the tree.
Gordon gave you a great idea, Mike! People need to see what TO DO. (They already see too many examples of what NOT to do!)
I think I had the same problem with a dwarf apple tree. I planted periwinkle around it and water it often. The tree died.
Dear Mike,
First let me say, I loved your Father’s Day tribute to your Dad. How wonderful to have left you with such pride for him ! Happy Father’s Day to You ! I have worked in landscaping for the past 15 years and I fully agree with you on the mulching techniques that have changed in the past few years. I have been complaining about the depth ’til I feel like “no-one” is listening or caring. Their responce to me is almost always the same, ” It helps keep the weeds and sucker branches from growing.” Or The owner says, “It looks so much neater. ” I have watched many trees, shrubs and flower beds die slowly because of this crazy practice that somebody came up with because they didn’t like weeding or whatever their reasoning , but I’m with you, I wish they would stop because I, for one, am really getting fed up with correcting their mistakes and having to start the gardens over.
Thanks for the tips to help educate the unknowing to help them realize what they are “really” doing to the plants and trees. Kathy
Dear Mike – I’m a big fan! Really love your articles – they are so informative and down-to-earth (no pun intended!) And I love the way you manage to provide all the pertinent details on a given topic – while seemingly talking “off the top of your your head”. That is a characteristic of a great teacher -and you are a natural…
I am not even afraid to ask what I think is probably a really stupid question! In the effort to conserve water loss from my very sandy soil I recently mulched around my entire garden areas, trees and shrubs with shredded bark mulch. I did read about it beforehand and did know to keep the depth below 2-3″ and away from trunks – but I do have a question… Prior to mulching everything (our water bill last summer almost put me in the Coronary Care Unit) I used to add sphagnum peat moss to the gardens every year. Now I wonder (a little late, I know…) how does one go about adding soil amendments to gardens that have a mulch over them? Are there different techniques depending on what is being added? For example, if I sprinkle fertilizer over the top of the mulch and water it in – will it actually make it down into the soil? Do I need to alter the amount of fertilizer I add if I don’t pull the mulch back and rake it in? How do I go about adding compost/humus/peat to gardens that are mulched with shredded bark mulch? Will compost make it down into the soil if I spread a layer over the mulch and lightly rake it in? Or do I need to pull all the mulch back, spread the compost, rake it in, and then rake the mulch back in place? Do I even need to add compost now that I have an organic mulch in place? Thanks again for all the great info!
Michele,
Good choice with the shredded hardwood bark mulch. It is the best for the plants and the soil. Hardwood bark mulch breaks down into really good organic matter that will enrich the soil. So now that you have mulch, I really would do anything for now. Bark mulch will harden and get crusty and you should loosen that up once a year. When you do that it will break down quickly. Then you can add compost if you like. But if you just continue to apply a light layer of mulch every other year you will enrich the soil. Just make sure that you loosen the mulch before you apply more.
This is very useful info! Thanks so much!
I haven’t been mulching– period, I am new to Indiana and mulching wasn’t common where I lived in the past. Maybe I should start?
Maybe you could do a pimmer on mulching?
Thanks, Shirley
You really don’t NEED to mulch. However, proper mulching helps conserve moisture for the roots of the tree, especially if it’s newly planted. It also means less frequent watering, which conserves water. ALWAYS keep mulch 6″ away from the trunk of the tree…and it shouldn’t be more that 3″ deep.
Hi Can I put mulch around my roses? Thank You Joan
Hi Mike,
I love the info you send out. I am a plant maniac, artist, landscaper and appreciated those who are passionate about these things. Maybe you should post a photo of proper mulching around trees so people can see a comparison.
Just a thought. Keep it coming.
Thanks,
Dixie
Dixie, you’re right. I’ll try and snap a photo and add it to the page first chance I get.
Hey Mike:
I love your articles….I am passing this on to my family and friends, keep up the good work.
God Bless
I recently ran into this issue on a property I work at. A number of different landscapers and gardeners had worked the property over the course of about seven years. I started noticing that lots of trees and bushes health was declining rapidly. So I started checking for water issues and pests to determine the problem. The problem was the mulch, not the plants. Over the years all the past gardeners topped the gardens once or twice a year with fresh humus or mulch to keep the gardens looking good, but rather than getting under the trees and bushes and removing old mulch from the top of the root ball to control depth, it was now piled up to close to a foot in places witch was suffocating the trees and shrubs and also starting to create trunk rot. Very important to rake back mulch to top of root ball to maintain 2-3 inches of cover when retopping gardens to maintain health and beauty of your plants. This really applies to all plants, not just trees and shrubs. So if you are a mulch user and your gardens are starting to decline, without signs of water stress(too much or too little)or pests, check your mulch to maintain proper depth so the plants do not become suffocated from lack of oxygen intake and to cut down problems with inadvertant layering and trunk rot.