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Leaf-bagging under scrutiny as a wasteful expense and pointless chore

leaf bags
In recent years, the leaf-disposal cost has increased substantially during periods when the Minnesota Department of Agriculture prohibits movement of certain tree products in an effort to contain the emerald ash borer.

From the weekend, one of those odd collisions of news that occur from time to time:

  • In Minneapolis, the city is extending its yard-waste pickup program for a final week, through Saturday, because leaves have been falling so much later than normal this year.
  • Meanwhile, in the New York City suburbs, local governments are campaigning aggressively against the raking and bagging of leaves as a practice that's bad for municipal budgets, not to mention homeowners' lawns and backs.

Residents of Westchester County are being urged to simply run over the leaves with a lawnmower, chopping them into fine mulch that can be left where it falls — or, alternatively, using a bagging attachment to gather the shreds for composting in a bin or heap behind the garage.

It was out of sheer laziness, I admit, that the lawnmower method was my standard leaf-management practice during most of my years living in the city, for there is no chore I loathe more than packaging leaves for pickup.

Typically I used the bagger and piled its gathered contents onto raised garden beds, covering them with black plastic to kill any pests and speed the leaves' conversion into fresh black loam for turning into the soil come spring.

Who knew I could have done my sad little lawn a favor by just leaving the shredded leaves in place?

Shredded leaves as weed fighters

Sam Bauer did. He teaches on turf and lawn matters in the University of Minnesota Extension program, and he told me that for well over a decade he and his colleagues have been preaching to homeowners on the many benefits of giving up the rake and making use of free turf builders falling from the trees.

Not only are chopped leaves good organic fertilizer, he said, there's research suggesting that certain types of leaves — black walnut and maple, for example — may suppress dandelions.

And the leaves of the honey locust — the most annoying material I had to manage on my Minneapolis lot, because of the quantity and cornflake size — not only need no shredding but deliver nitrogen to turf in especially high amounts.

Despite such obvious benefits, Bauer said he is aware of no local governments in the Twin Cities metro that are following the kind of strategy that Westchester officials are pressing to let the leaves stay put.

Their reasons, according to the New York Times, have to do as much with  cost to taxpayers, water quality and public safety as benefit to soils and lawns:

Westchester spends $3.5 million a year on private contractors who haul away leaves in tractor-trailers and bring them to commercial composting sites in places like Orange County, N.Y., and Connecticut. ....

[T]he county pays a private hauler about $40 for every ton of leaves that it takes away. Municipalities that provide leaf pickup service pay the county $15 a ton. So some county residents ultimately foot the bill through both municipal and county taxes.

County officials say mulching leaves in place not only improves soil quality, but also has other environmental and safety benefits for communities. Piles of leaves left at the curb can clog storm drains; the nitrogen and phosphorous leaching from decomposing leaves heaped by the street can also more easily enter the drains and harm local rivers. Additionally, leaf piles constrict already narrow streets and can conceal children.

The costs to Minneapolis

As it happens, costs in Minneapolis may be fairly comparable. Heidi Hamilton, the city's deputy director of public works, said the city budget for yard-waste collection is $2.87 million this year. On a per-ton basis, the cost to collect the leaves and haul them to one of two mass composting operations averages $45.

There is no way to determine how much of that expenditure goes just for leaves and how much for brush and other yard waste, although common sense and observation suggest that bagged leaves must account for the larger share by far.

And I was interested to learn that, in recent years, the leaf-disposal cost has increased substantially during periods when the Minnesota Department of Agriculture prohibits movement of certain tree products in an effort to contain the emerald ash borer.

Hamilton explained that the movement restrictions apply to brush and branches over an inch in diameter, but "because we don't really know what else might be in the bag with leaves, we have to put it all through the shredder. Every single bag."

(In St. Paul, by the way, leaves and other yard waste are banned from your normal trash pickup. So you'll have to haul the bags yourself, or hire someone to do it for you — more good reasons to compost.)

Hamilton checked with colleagues and learned that for a short while, more than 10 years ago, the city did some public-education work aimed at getting more people to chop the fallen foliage with lawnmowers and leave it where it fell.

No such efforts are under consideration now, she said, "but you've got me thinking."

If I've got you thinking about how to handle your last leaves of the season, Sam Bauer would like you to be sure you're doing things right.

Tips for the convert

First of all, with snow approaching, you don't want to leave your lawn covered with too thick a layer of leaf matter no matter how finely chopped.

"You want to be able to see grass coming up through the mulch,' he said, "with no more than 10 or 20 percent covered."

That might require several passes with the mower, and a special mulching blade can speed the process but isn't really necessary.

"The main thing is, when the snow comes, you don't want leaves sitting on the canopy" — what turf guys call the tip-top portion of the grass —because that just promotes winter kill, mold, moles and other pests.

So if you haven't been keeping up with your leaves and have a lot to deal with in the waning days, Bauer advises gathering them for a compost pile — either with the mower and bag attachment or, sigh, a rake. (Or, grrr, a leaf blower.)

Then resolve to do better next year.

"If you're going to be mulching all your leaves into the lawn, you need to be mowing more often than the grass itself needs," he said. "At least a couple of times a week, and maybe more if the leaves get heavy. So it takes a little more time than normal mowing."

But still better than raking and bagging, right?

"Oh, way better," he said.  "And it's a huge benefit not just to your lawn,  but to the whole environment."

Not to mention the city's waste-disposal budget.

* * *

For more information about composting leaves, either in place on the lawn or in a bin or pile, start with the U of M Extension page on the topic. For more information on Minneapolis policy and practices regarding yard waste, see this Public Works Department page.

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Comments (36)

Hmm. Just moved to a new

Hmm. Just moved to a new house, and I raked and filled ~50 bags this year. As appealing as composting is, my compost pile can't handle that amount of leaves. As for mulching-- I happily use my old reel mower, which is quiet, low-maintenance, and gas free. I honestly don't know which is worse for the environment-- once a week trucks picking up the leaves, or 20 small engines running "a couple of times a week, and maybe more" to mulch them.

A nice solution for those who have a power mower and not too many trees-- but for some of us the rake/bag/pick-up is still the best option. Plus, it's kind of fun-- kids helping out, jumping in piles, leaf fights, etc.

Heed what it says-not too thick no matter how finely chopped...

This is the first article I've seen that mentions that critical piece of information.

I mow up what I can and take the rest to the local compost site. Easy and, for my yard cheaper, than paying the local trash hauler to take my yard waste.

Another option

I was thinking the same thing as Dmitri -- what if you use a push mower? Because of the two-stroke engines on lawn mowers (unless they're electric) it's probably worse from greenhouse gas perspective for everyone to mow twice a week than for a truck to pick them up.

My alternative is to have almost no grass. I let the leaves stay where they fall for the winter in my gardens, then rake them to a perpetual pile under one oak tree in the back yard where grass won't grow anyway. This area is given over to native woodland plants that want that type of setting.

In a sense it's a big leaf compost pile -- about 25x25 -- that's home to ferns, jack in the pulpit, baneberry, ramps, and some hosta.

Balanced approach

I think it is hard to apply a one size fits all model for the issue of dealing with fall leaves. Some yards are nearly void of leaves, while others are overwhelmed by them. Composting in the backyard, 'mulching' into the lawn, and curbside collection should all be options available to homeowners.

I agree with the other comments concerning local air pollution caused by gas powered lawn mowers. I would expect that centralized collection of yard waste is much more efficient than everybody using gas mowers plus driving to the compost site on their own.

What's wrong with greenhouse gasses?

Maybe it's bad, but If it's causing "global warming", then I'm not catching on. Remember the late, cold spring we just had? Now the early start to winter? No snow, but I know for a fact this is early for our sustained low temperatures. NOAA just reports the quietest hurricane season in thirty years. Nothing ever adds up to even hint to global warming.

Nothing...

Except the darn ice keeps melting. Huh, I wonder how it does that with no warming going on. Maybe the melting point of water ice is changing due to some undetected change in the physical properties of the Universe? Hmmm, well my thermometer still says 32 degrees, so I guess not.

Snark aside, weather is not climate, and your back yard is not the world. Nothing adds up? Let's see - winters are shorter and wimpier, by a large margin, than when I was a kid in the 60's. The icecaps are melting. Glaciers are retreating. Atmospheric CO2 is climbing rapidly. The oceans are acidifying due to absorption of said CO2. Weather patterns are destabilizing. The jet stream is weakening, causing weather systems to stall more often, and even move east to west rather than the normal west to east. Wildlife populations and insect pests are changing their range, moving north. Alpine organisms are moving to higher altitudes (a brief adjustment, because they can only move so high.) The ocean is rising. Nighttime lows are higher, by far, than historical norms.

Yeah, you're right, nothing adds up to even hint to global warming. If you are insensate, have no memory of decades past, and do not read the news (Faux news excluded).

Global Warming

Jim, you're confusing local short term weather with global long term climate trends. That's like comparing an apple pie your mother baked with the trends in pastries across all bakeries in the United States: your scale is off by several magnitudes.

I, too, am in the lazy

I, too, am in the lazy chopper club and it's not unusual for me to take four or five passes over the leaves. I have a LOT of leaves and maybe there are too many finely chopped leaves, but I'm less concerned about the grass and more interested in the soil; I figure the grass can take care of itself but ultimately it's happier in decent soil. I notice the soil in the woods is pretty good soil.

The global warming question

Global Warming does not translate into "every part of the earth will be warmer all the time", so a late, cold spring followed by an early winter in Minnesota is not a counter to 'global warming'. What would be a counter to is if the thousands of temperature readings taken around the globe did not show a historical aggregate warming trend. Unfortunately they do.

It is interesting that a climate change denier would cite NOAA statistics on this hurricane season when the NOAA itself explicitly accepts that global warming is real, as can be seen here - http://www.ncdc.noaa.gov/cmb-faq/globalwarming.php. Why the need to spread misinformation about global warming in the comments of an article about picking up yard leaves?

It's a strange new world when

It's a strange new world when reporting what one actually experiences and witnesses - stubborn, cold springs and early winters... is labeled as "spreading misinformation". The retort I see over and over is "your back yard is not the world". My backyard is part of this globe and it is not under some inordinate warming. I am not mowing the lawn and serving lemonade at the picnic table in November. Quite the contrary, the ice rink is in already - never before have I had ice this early.

As I and at least one other

As I and at least one other commenter here have explained, local short term weather conditions are not valid indicators or counter-indicators of global warming. To present them as such is to spread misinformation. If you want to understand the scientific view on the matter, you could do much worse than read the NOAA website information I linked to.

Global Warming

Jim, again, your looking at the wrong scale. Your back yard is indeed part of the planet, but it is not in itself the entire world. When a heat wave hits do you then turn your argument around and say "oh yes, global warming is real"?

Do you recall when we had droughts this year punctuated by massive rains? That's caused by a weakened jet stream, which is not moving storm systems around as briskly as it once was. So weather patterns tend to stall out in one area, leaving them either parched or with more water than they can handle. Think of Duluth with the huge rain they had.

And why is the jet stream wimping out worse than a twelve year old who doesn't want to take the garbage out? Because the heat differential between the tropics and the pole is not as great as it used to be.

You're looking at the temperatures this spring and fall and claiming you've got all the answers figured out, conveniently ignoring recent winters that were extremely mild and summers that were extremely hot. Heck, didn't we recently have a winter with very little snow or cold? We might as well have been in Florida it felt so warm!

How about this scale?

Todd, If there was global warming, don't you think we would see something here locally to support it? For example, farmers here in MN for decades and decades have planted their fields in April/May and harvested in Sept/Oct. If the globe was warming, it seems that over the decades the seeds would be going in the ground earlier now than in 1900 - 1920. Not so, it is the same as it has always been. Therefore, how can there be global warming? The special interest groups continually cite some study of some far off place to make us believe something is happening. We are better off thinking for ourselves on this topic.

Growing Season

Actually many areas have already seen their growing season lengthen by a week on average. And that's before we've seen the worst of the effects of warming.

How can there be global warming you ask? It's a matter of simple math: if you pour more into a system than you take out, then the system fills up. In our case it's carbon dioxide through the burning of fossil fuels. Just like a bathtub, you can't dump more water into the tub than can go out the drain. Eventually the tub overflows and you have a problem that a little mopping isn't going to solve.

I do indeed think for myself on this as well as other issues. And I listen to the experts who have access to the primary research and data, which includes data points far in excess of the one outside my kitchen window.

At the end of the day you can't keep dumping material into a closed system and expect nothing to happen. Eventually the system is going to have to react to the new input and make changes accordingly. That's just common sense.

USDA Climate Zone change

Okay, Jim, I'll play your

Okay, Jim, I'll play your game. Remember January 1963? Probably not, but I was a freshman at the University of Minnesota Minneapolis campus that month, and I can remember five days in a row when the temperature failed to get above zero (I used to think it was a full week, but I checked the weather records, and it was only five). I was living in Frontier Hall that quarter, and my first class was clear across campus in Folwell Hall. I used every trick I could think of to avoid going out in the cold, cutting through as many buildings and steam tunnels as I could. There were five nights that month when the temperature dropped below minus 30 degrees. When is the last time you can remember that happening in the Twin Cities? I can't remember when it last got down to minus 20!

I know I'm talking local weather versus global climate, but you don't seem to understand the significance of that, so I'm playing by your rules, and my experience is that the area has warmed up by at least ten degrees in the last 50 years..

ok I'm on board with not bagging but...

... the city would also like us to stop burning gasoline in mowers.. I'd like to get an electric, but it wouldn't be able to do all that mulching.

I could buy a chipper/shredder, but raking up all the leaves, running them through the shredder, and spreading them all out again would be more work than bagging.

Leaves and Electric Mowers

Our Toro electric mower works great for mulching! The newer electric mowers are just as capable of mulching leaves as the gas powered mowers. Our South Minneapolis yard is covered with white birch, river birch, maple, green ash and cottonwood leaves and our electric mower chews them up quite nicely.

Hey ! Yea !

The old black aand decker electric has been mulching for years just fine.

Electric Mower

I'm using my grandparent's Westinghouse electric mower built in the '50s. It doesn't have all the fancy features of those new fangled you kids have these days, but it gets the job done.

For the leaves I just rake them onto the gardens and leave them there. They decompose over the fall and spring and help enrich the soil for my flowers come next year.

Isn't it fitting

That you can't throw your leaves in the trash even though they might be the one thing that will break down in the landfill within 30 years?

Trash

The problem with many landfills is that the trash doesn't break down, leaves included. In order for something to decompose it needs oxygen to help fuel the process. With most landfills, the trash is simply packed in tight and bulldozed over with a bit of dirt, which doesn't all air to circulate. A lot of land fill operators are getting better these days, but there's still a long way to go before they have good clean operations.

Another issue: even if the leaves do break down into good compost, it's not something you would want to use on your garden. Land fills are rife with toxic compounds, from plastics to oil, medicine, and heavy metals. It's pretty much one big poisonous toxic brew that if put on your garden would turn it into a superfund site.

The ultimate objective is to get trash hauling to the point where nothing is landfilled and it's all recycled, not add more useable goods to a hole in the ground where no one can make use of it.

The real story here...

...is that the city of Minneapolis is paying the cost of getting rid of leaves-a process that most cities in Minnesota let homeowners pay the freight for.

It seems to me Mr. Halonen's

It seems to me Mr. Halonen's view on climate change equates with "there is no hunger in the world, I had a nice lunch today"

Do not confuse the terminology

It's not "climate change", it's "global warming". The special interest groups changed it to climate change - only because they couldn't prove warming.... and they had quite a movement going.

Different special interest group changed term

Sorry, a different special interest group changed the term global warming to climate change. It was not because they couldn't prove warming. It was because science could. Republican pollster Frank Luntz is credited with encouraging Republican politicians to use the term "climate change" rather than "global warming" because it seemed more benign.

"Climate change" vs "global warming"

"Climate change" vs "global warming" is a false debate. Climate researchers have used the terms more or less interchangeably since the 1950s, though it could be argued that global warming caused by humans is what is causing climate change today. Historically, there have been many causes of climate change -- Milankovitch cycles, plate tectonics, chemical weathering, extensive volcanism extending over centuries, asteroid impacts -- but the main one operating today is global warming caused by an increase in atmospheric CO2.

You may as well state - I did

You may as well state - I did not get hit by a car today, so there is no pedestrian/auto accidents.

Hey, Minneapolitans pay for that service

I live in Linden Hills, not too far from France Avenue and the Edina border. When we were looking for a house, we looked at a few that were 6-8 blocks away on the Edina side of the line. The taxes on a comparable house in Edina were less than half of those for the Minneapolis house.

Jim, you are still missing the point...

You are still confusing weather with climate.

Sooner or later, weather

Sooner or later, weather means climate with all the cold temperature records being set.

But...

Jim what records? Records globally? Again, local weather is not the issue. You still haven't shown empirically that global temps have become cooler. Until you do Jim you have no argument. So, Jim, are you going to show us peer reviewed data demonstrating otherwise?

Willful ignorance

It's tough to make a dent in willful ignorance.

Weather

What about all the warm weather records being set? Don'y they count?

Lawn mower exhaust is a minimal and not a problem.

Two cycle lawnmowers have not been made for years. Modern lawn mowers are not only four cycle, but now over head valve as well. They use minute quantities of fuel, and their contribution compared to a trip to the store in a car is miniscule. This notion that lawn mowers are a huge environmental problem is just nonsense.

Lawn Mowers

Mark, new lawn mowers may be very miserly with their exhaust fumes, but there are still a lot of old models still in use.