View Full Version : a bunch of mulched up leaves

11-03-2003, 03:23 PM

I posted in the commercial question about mulching up leaves. My actual question was about all the complicated things the pro LCO's worry about -- deck design, blade design, etc.

I'm just Joe Homeowner, and after letting my kid play in the pile for a couple weeks, I decided to mulch it up with my cheap little electric mower.

I got some rather harsh responses, but one question that came up is about mulching a big pile of leaves being bad -- too much nitrogen.

I can't imagine dried out leaves having much nitrogen left in them. How would a big pile of leaves mulched up compare to something like the cracked corn that has been discussed here?

Would the leaves have much left in them to serve as a carbon or protein source? These were so dry, they pretty much just turned to dust. After three passes, there was absolutely nothing left. I tried to use my blower to get rid of anything that was left and gave up as there was nothing to blow.

11-03-2003, 03:35 PM
Dried leaves are more of a carbon source than a nitrogen source when dry.
Some of the response you got was because of your presentation of your thoughts. LCO'S deal with conditions that are typically less than optimal.Mulching dry leaves is easy.....Many times they are not dry but very wet etc. etc.
The problem with mulching too many leaves into the lawn is the change in ph that will occur in time.

11-03-2003, 03:36 PM
Did a search on google, here is what I found...


11-03-2003, 07:12 PM
Why even star treads if you're not going to follow?, we're a bunch of people willing to discuss a topic not argue, everyday I learn many new things in this site, maybe you're into something just have to come with a proof, I find real hard to believe a 2' pile would turn into dust with a 21" in just 3 passes, like I said bring some proof if you really want to make a point.
Did you know we had a homeowners forum?

I don't think I would have the nerve to tell you how to do your job, unless I had proof of it, and maybe even then you wouldn't listen.

There's years and years in research before a mower can make out for sale, and there's so many brands out there, (We all know which is the best dont we? :) )
I would love to be able to use a 21" electric push mower in 2', hell even 4" of leaves and make'em dissaper, I would have so little overhead.

Why do you think we talk so much about leaves and pitch decks, baffles, etc.?
In case you haven't realize this is a lanwsite forum.
Stick around you might learn something, cause I know I learned a lot from your post.

11-03-2003, 09:03 PM
Good info moguy,
Problem I see with it though is that they are both only 1 year studies. Something a little more long term may be needed.

dan deutekom
11-03-2003, 09:49 PM
In the garden park where I work we always chop the leaves as they fall. We put gator blades on the mowers and mow twice a week. The park has a lot of maples so there are a lot of leaves. Have done this now for 5 years and have seen no ill effects. We do have to be careful that we spread the leaves evenly when we are mowing and many times we will make 2 or 3 passes to chop them fine enough. In the spring we do end up doing a little bit of remedial raking and seeding where the leaves ended up being too thick and choking out the grass but it still is a whole lot less work than picking up and removing all the leaves.

11-03-2003, 10:42 PM
Well put, Dan....

As long as the leaves are cut as they fall, they get chopped up and disappear.

It is clear that leaf cleanups are good money makers. But i wonder if in the long run if you did in fact cut each account twice a week and charge accordingly would the bottom line be the same? And as Dan said it is alot less work.

Of course if you have a lot of accounts maybe mowing twice a week is not practical. Or....Maybe the time spent blowing, picking up and disposing of the leaves would work out the same as time spent mulching? Or am i way off base?


11-04-2003, 12:24 AM
Purdue has worked with leaf mulching into turf for years. Quick search found: http://www.agry.purdue.edu/turf/report/1997/leaf.htm . No negatives found that I know of, and improvement of soil has been noted in recent years. More detailed report somewhere - he has been mulching in at least 6" of leaves on test plots.

However, Zac is working mostly with maple leaves, which do disintegrate pretty well. Our area is mostly oaks, and I have yet to see any machine that will grind wet oak leaves to dust.

On the pH effects of mulching leaves: oak leaves are said to be very acidic. I know a man here who tilled 6" of oak leaves into his vegetable garden every fall, and another 4-6" in the spring. Every year for 27 years he sent in a soil sample to find when he was changing the pH too much, so he would quit the oak leaves. After 27 years, he quit getting the soil test, because pH had not changed at all in that time. A pH change may occur from leaf mulching, but after 100s or 1000s of years.

The few here who try to mulch oak leaves 100% usually wind up smothering the lawn in places. Have even seen lawns smothered from mulch mowing maple and elm leaves.

11-04-2003, 11:30 AM
Just thought I'd offer my experience on this thread.

I'm not an LCO but a homeowner who does take care of a good size piece of property.

I have been mulching all of my leaves now for 7 years.
The mix of trees are all that have been mentioned in this thread.
I'm attaching a photo to give you the perspective of the amount of trees on the property. I would say my biggest depositors are the oaks followed by the hickory and ash trees. And yes those are the most difficult to process.

I have always after the final mulching applied dolomitic limestone at the rate of 10# per 1000 sq ft.

I have IMHO had good success with this effort and am pleased with the lawn. Please take into consideration that the photo was taken this spring during a rather rainy period here in PA. Also this lawn is "abused" since it doubles as the exercise yard for the dogs that my better half raises. They are rather large animals that have no respect for grass. lol

As far as turning the leaves to dust.... can't say that I have been able to get that good of a result. What I find is that the mulching process will get the leaves down to about 1/4" pieces on average.

For the first 6 years I used a 33" walk-behind mulching mower (Troy-Bilt) and this year went to a 54" Hustler SWB. The Hustler has definitely out performed the TB in the mulching and cutting capabilities.

Hope this helps.

The Lawn Boy Pro
11-05-2003, 10:18 AM
When you go by a pond in the fall, what do you smell? All those leaves decomposing in the water-which means SOMETHING is in the leaves still! When you mulch leaves on a lawn, you have to be VERY careful not to do too many, becasue you could very well be changing the PH rate drastically. Just a warning.

11-06-2003, 03:30 AM
One generally accepted organic practice is to continue to mulch/mow the lawn at the same height. Some yards have quite a bit of litter and need to be mowed more often or make several passes to keep from smothering the grass (as GroundKprs said). In organic yards pH is not usually a consideration when mulch/mowing leaves.

What is good about mulching leaves into the soil is that they require fungi to decompose them, and lawns are woefully short on good fungi. If you cover the top of the grass with leaves and leave them for the winter, you will undoubtedly develop disease fungi under there. But when you chop them fine and allow them to drop in between grass blades, there is too much air circulation for the disease fungi to develop.

The other way to get fungi into the lawn is to use a fungally dominated compost or a fungal compost tea regularly.

11-07-2003, 09:25 PM
educate me,
Why is ph not usually a consideration in organic lawns when mulching leaves?

11-12-2003, 03:43 PM
pH is not usually a concern in organic turf because there is such a predomination (is that a word? - must be; my spell checker let it go) of humic acids in the soil. Humic acids are buffered acids. This means it takes a LOT of strong acid or strong base to change the pH of a buffered acid even just a little. The humic acids are buffered right at a pH of 7.00000000 - maybe a little less or more. Once the microbes have been cranking on organic fertilizer for a year or so, the buffered humic acids will predominate and it becomes very hard to change the pH - especially by adding a weak acid like tannin from tree leaves. Out in the wild, the pH is usually held between 6.5 and 7.5 with healthy microbes.

Lawns that have not had much organic fertilizer applied in the past will act different. These lawns have no wealth of healthy microbes in there building up humic acids. (by the way, humic acids are very dark brown to black in color; hence the fertility of the black land soils) Some organic fertilizers, ammonium sulfate in particular, are strong acidifiers and will lower the "unprotected" soil pH toward the acid side with relative ease. In fact the pH can be lowered to the point where it becomes difficult to reestablish healthy microbes in the soil without a pH adjustment with lime.

11-12-2003, 09:01 PM
Thanks David.