Giant mulch rings...never seen one, and don't believe in them!

[pdqdl]

Every time someone mentions lawn and trees in the same breath (here at ArboristSite), someone always seems to pipe in with the comment to add mulch out to the dripline.

Sorry, I simply don't get it.

Kansas City is FILLED with trees. We fight them like weeds. If you don't pay attention, in 15 years, you don't have a lawn, you have a forest. At least 1/2 of the tree work we get is removing trees that never should have been where they ended up growing.

We have heavy clay soil (Clay County, in fact!), rich bottom land with perfect soil, and we have our share of sandy soil and gravel/rocky soil. Sorry, no flint or granite soils here, everything is limestone.

I have never seen a tree killed off by the lawn, and I have never seen a mature tree mulched to the dripline, either.

I can look down every single street in this town and point out where the larger trees have killed off the lawn: bare dirt beneath them. In fact, nearly every homeowner in town is aware of this single, compelling fact: Too many trees, and you won't have any lawn. Period.

WHY do you folks keep telling us to increase the mulch ring to protect the tree from the lawn?

Is Kansas City a tree oasis, where trees thrive better than elsewhere? I have always considered trees the "apex predator" of the plant kingdom. Please tell me where I have it wrong!

I promise to listen carefully, but only to compelling, thoughtful, and well documented arguments.

 

[chewbacca]

You make a compelling point. I am from Ohio. I now live in north Idaho. Climate and soil profile are drastically different in those two areas. Large deciduous trees do well in ohio. They naturally have what they need there (for the most part). Here in idaho, they are not native. We have very dry summers and we have to irrigate anything we plant that is not native. Because of that fact alone (and maybe others), trees benefit from not having to compete for water with lawn. You're absolutely right. Every situation is different and should be examined closely. In the world of arboriculture (and other fields too - I'm sure), a notion becomes popular and almost becomes law. To the point where anyone who doesn't follow suit is looked down upon. Some people take themselves way too seriously. If the benefits gained from mulching trees don't outweigh the costs (in your experience), don't do it. Can't worry about what everyone else thinks. Cheers

 

[outofmytree]

I know what you mean pdqdl. I have seen only a few Moreton Bay Figs which are mulched to the dripline and those babies kill off grass anyway. I think the logic behind mulching to dripline is the fact that most plant books show water gathering roots extend that far. It would also be worth noting that lawns are often over fertilised with NPK and this contributes to tree nutrition problems but thats the extent of my meager knowledge.

Somebody heeeeeeelp!

 

[Glennak]

So what a great way to control weeds, plant a tree, got to be better than chopping the top off the weeds every week what a waste of time.

 

[asthesun]

at alot of commercial sites i do tree work, there's mulch rings, there to protect the trees from idiot lawn maintenance worker's mowers and weedwackers.

 

[S Mc]

pdqdl, I see in your sign off that you state you are a certified arborist, and yet you make the statement "I have always considered trees the 'apex predator' of the plant kingdom". Viewing trees in this manner sounds counter to what an arborist is or should be.

You are evidently incredibly lucky to be in the perfect environment for tree growth. And yet for some reason you are claiming it is a curse.

Perhaps where your logic is erring is latching onto the phrase "protecting the tree from the lawn". It is well documented that trees and turf compete. Where trees predominate the turf will suffer. Where the lawn is given all the care, the trees suffer. A golf course may have the most magnificient appearing turf imaginable. It is a contrived, artificial environment. If that is the appearance your clients want, you need to adjust your recommendations to achieve that. Unfortunately for the environment, that generally means pumping untold amounts of chemicals. (But that is a whole other post and rant.)

Picture a forest...sparse, native grasses.

Picture a prairie, sparse, scattered trees.

This would be the natural order of things. People unfortunately try to have everything, all at once, with no thought as to what is going to blend and coexist.

The trees and grass in your area are desperately trying to tell you that they don't want to cohabitate. If your solution to no grass under a tree is to constantly try to thin the tree or raise the crown, you are in fact fighting a losing battle. We have clients that simply will not give up their grass too close to the tree, and we tell them this is a continual battle that will require maintenance.

"Too many trees, and you won't have any lawn. Period" This sentence is true, pdqdl. But then why not go in proactively to your clients and help them select their best specimens, get rid of the "weed" trees and set up a realistic management schedule for their landscape that will minimize the use of chemicals and annoyance of running into limbs or debarking the trunks with their lawn mower?

Trees will survive without the mulch ring. They simply will survive and thrive better with it. Your client has a dead spot, bare soil under the tree...why NOT mulch it and make it look attractive?

There is much documented evidence that roots thrive better under mulch. I am surprised as a certified arborist you have not read these reports. Google Kew Gardens. After a hurricane in the 1980s that blew over a great many trees, they discovered the roots under the grass areas were significantly less than the ones under mulch areas. Every tree that can now has a mulch ring.

Sylvia

 

[Dadatwins]

One of the functions of having a mulch ring is to make the tree site as natural as the wooded setting that trees come from. Trees growing in a natural forest have the benefit of leaves dropping and breaking down into nutrients for the tree to retake up and continue the cycle. This is how trees have survived for millennium, they create and use their own waste. Place a tree in front of a house and then add a lawn service that takes all the grass clippings away all year long, takes away all the leaves in the fall and the tree is left sitting in the same soil that it has been planted in. Without the natural benefit of the organic matter the tree will start to decline as the roots can only pull so much out of the soil. By adding a natural mulch ring, not rock or plastic, arborist are trying to duplicate the natural environment of the forest but still satisfy the aesthetics that homeowners want. In a perfect world a mulch ring to the drip-line would be ideal, but we all know that is very unlikely. As for large mature tree needing a bigger mulch ring, bigger trees needs more food.

 

[TreEmergencyB]

i think the biggest advantage of mulch rings around trees is to keep them damn landscrapers from dinging them up with there mowers and weed wackers, make it out the the drip line and you will not only protect the trunk but the lower canopy also.

 

[D Mc]

...I have never seen a tree killed off by the lawn, and I have never seen a mature tree mulched to the dripline, either....

How is this possible? Have you not seen young trees with their cambium irreparably damaged by routine lawn maintenance? Herbicide-sensitive trees succumb to weed and feed products? Preexisting trees decline after new lawns were set under their canopies? These are common occurances that I have seen many examples.

Trees are tough. We can all point to the magnificent tree in a grass area and say "See?" I can also point out magnificent trees growing out of rocks on a dry mountainside. But if we tried to perpetuate that environment in our landscape, we would be doomed to failure as these are the exceptions.

Dave

 

[treemandan]

pdqdl, I see in your sign off that you state you are a certified arborist, and yet you make the statement "I have always considered trees the 'apex predator' of the plant kingdom". Viewing trees in this manner sounds counter to what an arborist is or should be.

You are evidently incredibly lucky to be in the perfect environment for tree growth. And yet for some reason you are claiming it is a curse.

Perhaps where your logic is erring is latching onto the phrase "protecting the tree from the lawn". It is well documented that trees and turf compete. Where trees predominate the turf will suffer. Where the lawn is given all the care, the trees suffer. A golf course may have the most magnificient appearing turf imaginable. It is a contrived, artificial environment. If that is the appearance your clients want, you need to adjust your recommendations to achieve that. Unfortunately for the environment, that generally means pumping untold amounts of chemicals. (But that is a whole other post and rant.)

Picture a forest...sparse, native grasses.

Picture a prairie, sparse, scattered trees.

This would be the natural order of things. People unfortunately try to have everything, all at once, with no thought as to what is going to blend and coexist.

The trees and grass in your area are desperately trying to tell you that they don't want to cohabitate. If your solution to no grass under a tree is to constantly try to thin the tree or raise the crown, you are in fact fighting a losing battle. We have clients that simply will not give up their grass too close to the tree, and we tell them this is a continual battle that will require maintenance.

"Too many trees, and you won't have any lawn. Period" This sentence is true, pdqdl. But then why not go in proactively to your clients and help them select their best specimens, get rid of the "weed" trees and set up a realistic management schedule for their landscape that will minimize the use of chemicals and annoyance of running into limbs or debarking the trunks with their lawn mower?

Trees will survive without the mulch ring. They simply will survive and thrive better with it. Your client has a dead spot, bare soil under the tree...why NOT mulch it and make it look attractive?

There is much documented evidence that roots thrive better under mulch. I am surprised as a certified arborist you have not read these reports. Google Kew Gardens. After a hurricane in the 1980s that blew over a great many trees, they discovered the roots under the grass areas were significantly less than the ones under mulch areas. Every tree that can now has a mulch ring.

Sylvia

No doubt we have all seen what too much mulch can do. But they keep heaping it on. I try to sell a de-mulching but rarely get the job. Basically the de-mulching is making the ring bigger in dia and thinner in thickness,

Kinda reminds of a show I saw on one of those landsrcaping channels. Gino's Crew. What a laugh.

 

[treemandan]

i think the biggest advantage of mulch rings around trees is to keep them damn landscrapers from dinging them up with there mowers and weed wackers, make it out the the drip line and you will not only protect the trunk but the lower canopy also.

I agree.

I have to say that trying to control my weedwacker isn't the easiest thing to do. And above ground roots? Wow!

 

[John Paul Sanborn]

No doubt we have all seen what too much mulch can do. But they keep heaping it on. I try to sell a de-mulching but rarely get the job. Basically the de-mulching is making the ring bigger in dia and thinner in thickness

This is because mulch has become a commodity, so now they sell it vs the service of mulching. The more mulch they sell the better off the vendor is. The other problem is that what is sold as mulch is often a wood waste product, instead of a good healthy compost.

Recent studies of chemical uptake shows that the first 3-5 feet from the trunk does the majority of the translocation to the crown. One theory is that the rest of the system is there to maintain the support and to locate supplies for times of stress.

Yes, mulch to the dripline is hyperbole, there is not scientific evidence to back up the theory. My problem with this method is that it encourages the planting of annual gardens in the area to fill in the blank space. Perennials I like, especially if they are deep rooting prairie types that will help with water penetration....but that is another thread.

Trees are tough. We can all point to the magnificent tree in a grass area and say "See?" I can also point out magnificent trees growing out of rocks on a dry mountainside. But if we tried to perpetuate that environment in our landscape, we would be doomed to failure as these are the exceptions.

This is the whole purpose of Arboriculture: a tree planted in a landscape has the cards stacked against it in so many ways. As stated above the removal of nutrient cycling form the urban environment is a big problem, mechanical injury, unskilled pruning and being a species introduced to a non-native environment are at the top of the list.

Taking the anecdote of the "wild" tree form a different angle can put it into perspective for the uninformed; "How many thousands of trees died in that same location as the 300 year old tree grew, or for that matter a 60 year old tree?" A tree in the wild is a numbers game, a tree in a landscape needsto be maintained to grow to it's full potential.

 

[Bigus Termitius]

Hey pdqdl,

I'd support a mulch ring a few feet out anyway, maybe more, especially if there is to be a landscape, playarea, picnic table or what not.

Out to the dripline seems to me more applicable to younger trees in general. To fill in the gap on larger, more established trees, I would do a soil test, make any adjustments needed, and recommend a shade grass mix.

Years ago, my stepdad was wanting to cut down a tree for the bare earth under the canopy. I worked up the soil a bit and planted the proper variety of grass and now no more mud mess or bare earth in the front yard.

Just my 2 cents.

 

[TreEmergencyB]

I agree.

I have to say that trying to control my weedwacker isn't the easiest thing to do. And above ground roots? Wow!

never mind hitting ground roots not good for the tree or your mower
:notrolls2:

 

[tree md]

Just for the record, what is the best mulch to use and how deep should it be?

Also, I had to raise a bed for perennials yesterday on one of the properties I take care of. A little out of my realm but I am doing it as a favor for the Pres. of the HOA. I raised the bed using a soil developed by one of our local college horticulture departments but I had to raise the bed over the roots system of a young maple. I think the maple is like 13 years old, maybe 6-8" DBH and maybe 15' tall. I was sure not to cover the root flare or stem but I had to raise the bed about 12-14" over the root system. Any problem with that?

 

[TheTreeSpyder]

The mulching is also a way to compete for space, shut out lite, retain water, stabilize temp, spread out forces to a larger foot print and provide dynamic absorption (both to not compress soil sea air space. Low branchings would also provide less light and obstacle to traffic, thereby also limiting competition, conserving water and again less compressed ground. Low branchings would also help keep light out, keep rain more to outside, and downward pointing branches help deliver water outwards (whereby upward pointing branchings tend to run water towards trunk, lowest branchings providing final routing etc. (Light thru branches is green, with red mined out of white lite, leaving light 'anemic' for plant growth, but in a band we are more sensitive to, so it seems brighter than it is.. As another form of fierce competition for life giving ground). These things are all orchestrated to the same ends. A tree out of a woods, already has odds tilted, just because it survives, does not mean it thrives.

It is not so much the air in the soil we save by less compression, but rather the air space that air, water, growth etc. can create rich, Earth, and also make it permeable. This allows a rich fauna of life, bio-diversity matters in the sea of soil! There is only so much energy, for growth etc. The 'net income' of the roots; is the riches they bring in less the expenditure to deliver etc. Less permeable ground/less airspace/more compact, is going to be less rich, and cost more energy to work for those lesser riches (double loss).

Air only penetrates so deep, and even mulch has weight, we neither want to compress, nor smother Mother Earth by too much of a good thing/mulch. Nor do we want mulch against trunk,nor on the Natural ramping of the root crown, that would serve it away from the trunk. Even though in our lysdexic ways; that is where it is first placed! No, Know; Bad ! Trunk and root crown tissue is more like above ground tissue, not root tissue, trunk and root crown must breathe etc.

We all do what we must, but it is better to have a good imagery of what is in the balance; especially when advising others. The 'new' school of tree biology is quiet simple, a tree is a living, responding thing; not just a board to dictate to as we hammer nails into it, or the tree bones we build our homes with-that we are most familiar. This is the pivotal paradigm to what we think wee know. Understanding trees can inspire a lot of respect for them!

 

[M.D. Vaden]

How is this possible? Have you not seen young trees with their cambium irreparably damaged by routine lawn maintenance? ......

That would be by the person and machine. I think they meant by the grass itself.

In my work and at the homes I've lived at, even back to childhood, I can't put my finger on a tree that I can say was killed or put into ill health by having grass under it.

The most damage I've seen, was at the country clubs in low areas that were wet, were compaction from mowers and poor drainage were a problem. The drainage would have been bad even without the grass.

So I more or less agree that grass may not be much of a problem, although I do expect optimum health for many trees that are mulched because so more become premium conditions.

 

[chewbacca]

Just for the record, what is the best mulch to use and how deep should it be?

Also, I had to raise a bed for perennials yesterday on one of the properties I take care of. A little out of my realm but I am doing it as a favor for the Pres. of the HOA. I raised the bed using a soil developed by one of our local college horticulture departments but I had to raise the bed over the roots system of a young maple. I think the maple is like 13 years old, maybe 6-8" DBH and maybe 15' tall. I was sure not to cover the root flare or stem but I had to raise the bed about 12-14" over the root system. Any problem with that?

Yeah, I'd say 12-14" of additional soil on the root system of a tree that size is too much. Something like 90% of a trees roots are within 12-18" of the soil surface (depending on species). Those roots need oxygen, which is one reason why they're so close to the surface. By adding that much soil, you run the risk of effectively smothering those roots. I'm not saying you'll notice a decline in the tree. But, I'd be willing to say that if the tree's roots cannot grow upward closer to the surface quickly enough, it will exhaust it's "energy" reserves and, at that point, you will notice a decline in the tree. Could end up not noticing anything or it could end up bad. At any rate, it's best not to do it. Good luck.

 

[D Mc]

That would be by the person and machine. I think they meant by the grass itself.

It is a moot point when you cannot have one without the other. This discussion is in regards to landscaped yards.

You are particularly qualified to answer this: why not put a mulch ring around the tree? As a professional landscaper, would it ever be appropriate to plant non-compatible species together?

If we, as arborists, don't get it, how can we expect the homeowner to?

Dave

 

[M.D. Vaden]

It is a moot point when you cannot have one without the other. This discussion is in regards to landscaped yards.

You are particularly qualified to answer this: why not put a mulch ring around the tree? As a professional landscaper, would it ever be appropriate to plant non-compatible species together?

If we, as arborists, don't get it, how can we expect the homeowner to?

Dave

Little 3' ring - sure pretty easy.

Most of the good landscapers here can maintain turf to within a foot of the trunk without any damage. But a ring a few feet radius or circumference would not be hard.

Would really look dorky in small yards. And the reason many homeowners don't want them, is that they reduce the amount of lawn to use.

In big landscapes, the circles can look pretty nice.

Below is a before and after of one landscape renovation. I revisited after 5 years, and the homeowner maintained the grass meticulously around the maple without damaging the bark. I think a circle would look rediculous - even a small square.

Thus - he as an amateur shows he can do it right.

If he sells the place, the next person can cut the tree ring out and mulch if they choose to.

There is about 2 weeks between these two images.