Where are you putting them? Lawn? Garden?

Interesting, why should I collect them and sprinkle them into the lawn?

It does bring up an interesting point: Most of the time, I do let them fall into the lawn while they are being cut yet I have never seen any build up.

The amount of clippings for the gardens are a bit more aggressive and the blades are longer. Right now, three weeks of tight layers are at about 1".

Sorry I missed the word 'garden' in the title lol. My feeling is the more mulch the better. A few inches is best. Definitely more than 1. Just don't put it right on the plants.

I don't like to use pure clippings. Regardless of how little you put on at one time, they tend to mat with rain. To get best results, you'd need to keep them loose and fluffy to allow air to move though them.

I've had clumps last for a long time without breaking down much at all.

However, it seems to me that the only limits on how many layers you can add is if it becomes difficult for the soil to 'breathe' and the mulch stops doing it's job. For example, when grass 'mats', water can bead off and not penetrate the soil.

Another thing to keep in mind is what do you do with the grass after the season ends? If you hope to turn it under, and the grass does become a tight mat, it may not decompose well.

How does one keep them "Loose and fluffy"? The only clumps I have ever seen were when I left a mass of clippings in a single pile. This is not the case.

In my 60 years of gardening, I have never seen water be prevented from penetrating into the soil due to layers of any kind of mulch.

Generally, I do nothing for the gardens other than blowing leaf chips into the gardens and I never "turn it under". It is unnatural. No one turns under the compost in the forest.

"Just don't put it right on the plants."

I figure that you mean not to cover the plant even partially as the covered leaves would rot. What problem, if any, would it be if the stems of the plants had grass clippings in contact?

"Sorry I missed the word 'garden' in the title lol."

Actually, you did not miss it. I went back in and added after your comment.

The biggest question for me would be what do your neighbors put on their lawn? Need to know that before putting those clippings near your plants.

"How does one keep them "Loose and fluffy"? The only clumps I have ever
seen were when I left a mass of clippings in a single pile. This is not
the case. I have never seen water be prevented from penetrating into the soil due to layers of any kind of mulch. Generally, I do nothing for the gardens other than blowing leaf chips
into the gardens and I never "turn it under". It is unnatural. No one
turns under the compost in the forest."

I'll tell you what... go plant a tomato transplant or a bean seed in a sunny clearing of the forest without tilling the ground. Annual vegetables are not on the same par, nor have the same needs as trees and forest undergrowth. They take a very long time to get established... years in fact. If you have soil that is friable enough for no-till, and you aren't experiencing problems, then as I mentioned... your only limits are...

So, as I said, if you aren't experiencing problems, then... what's the problem?... just keep doing what you're doing. I've used pure grass clippings and they mat and cause water to bead off. I don't know, maybe we have harder rain storms here that cause the water to run off without soaking in?

Instead of grass clippings, I let my yard grow up until about seed time. I then 'mow' it down by hand with a swing blade. I then collect that 'hay' and use it as mulch. That hay softens the force of the rain and allows the water to seep though. We have a lot of biological activity in my climate though, and an 8" layer of that hay shows bare Earth after 4 months.

I use the clippings from my garden paths to mulch the pepper pots in summer (this will be grass and dandelions mostly). It is very difficult to overdo it. Over a pepper growing season, the pots (which have lots of earthworms in), consume easily one foot unpacked of the stuff. It just needs to be reapplied every 3 weeks or so.

OK, a lot of good suggestion here. I have been increasing the use of grass clippings and chipped leaf mulch over the years without any adverse situation. I guess taht I was wondering if there was a realistic limit to it. I think I will cut back and see how it all turns out. I do know that the number of weeds has dropped considerably though. I may have even broken the three year cycle.

"The biggest question for me would be what do your neighbors put on their
lawn? Need to know that before putting those clippings near your
plants."

I have yet to hear from anyone who has first hand knowledge concerning this.
Do you?

How much of all the talk is supposition?

An inch is just about right since more could cause those clippings to heat up enough to damage the plants they are supposed to be protecting. When I did use grass clippings fro mulch I found quite early on about the tendency of those clippings to heat up due to the high levels of Nitrogen they contain.

emerogork, you're in zone 5, how fast do they breakdown? Does it seem that they just keep getting thicker, and thicker? Or do they seem to breakdown in proportion to the time it takes to add more?

Good point, another reason to recess to reassess.

I once tried to use corrugated paper to prevent weeds. I set it down in the fall and used light compost to hold it in place. By the spring time absolutely nothing was left of the paper other than the occasional staple or strip of tape that held the boxes together.

I am going to stop adding clippings and take measurements over the summer and fall. It will be interesting to see if weeds come up.

As far as water run-off due to drying clippings, with gardens 10' - 15' deep and 80' long, where is it going to go?

I collect some fall leaves in bags so they stay dry (most of them go into the leaf bin but some are kept out). In spring, I mix them on a tarp with grass clippings and use that to mulch the garden. Probably 4-6" thick max. The dry curly leaves keep the whole thing fluffed up for awhile. By fall you can just about see the dirt which means all that stuff has been decomposed by microbes or eaten by bugs. Sometimes I'll add wood planer shavings to the mix. Any kind of wood chips would work if you have them. They are slower to decompose but that's OK, you are trying to mulch after all.

Last fall, I still had about 12 cu ft of finely chopped leaves left after liberally covering my raised beds and around the flower beds. The heap stayed dry because it filled two wheel barrows and was covered with a tarp. I wondered if mice would make a home in it.

This spring it was extremely useful so I guess I will plan for more in the fall.

I have serious reservations about using any form of wood though. I understand that it uses up nitrogen as it breaks down.

Not if it's on TOP of the soil. Just don't till it in. The limited contact with the surface of the soil prevents any nitrogen depletion.

Nitrogen isn't used up. It is tied up in the carbon as part of the compost cycle.

And said nitrogen is taken from where?

Its destination is a moot point if the plants you are trying to grow need it.

Unless you are burying the wood chips you will have no nitrogen depletion. The nitrogen that makes up 70% of our atmosphere can not be used by plants. Bacteria and fungus go through the process of nitrogen fixation in which they break down the hard to break N2(nitrogen in our atmosphere) into NH3 (ammonia) which is further broken down into nitrogen compunds that plants feed on.

So what you are saying is plants have no use for nitrogen and cannot benefit from any by-product, chemical operation, or otherwise any activity assisted by nitrogen, Yes?

No I am saying that most plants can't use the most common form of nitrogen (the gas in our atmosphere) because the N2 bond is too strong. The nitrogen in the soil that your plants feed on has been broken down several times by bacteria.

Your plants roots are below soil and your mulch is above the soil so there is no conflict of interest.

"The nitrogen in the soil that your plants feed on has been broken down several times by bacteria."

So, in the absence of nitrogen, what happens?

Are you burying the wood or using it as mulch?

" I've used pure grass clippings and they mat and cause water to bead off."

So what is all this hoopla about water running off when using grass clippings? I am just not seeing it and wonder where this tale originates.

Plain and simple, in my experience, the water freely seeps into the soil no matter how deep the clippings are piled up.

After applying them for the last month, I have locations where the accumulation is only an inch to an area where I have it is over 6". I even have a location where I dumped a bag full and neglected to spread it and have yet seen any beading off.

Figure it this way: Anyone who believes that grass clippings will make the water run off and not benefit the plants should describe the technique on how to make it happen. I would like to see this for myself.

I am sure that this is a myth that deserves to be debunked.
Prove me wrong. I want to see it happen first hand.

I have used grass clippings as a mulch for a long time. My only critique of grass clippings is they tend to blow away with high wind.

As I said... when the grass clippings mat, which they have a tendency to do, water beads off without soaking in effectively. I garden in mounded 4' wide beds, and I prefer a mulch that allows the water to pass freely through the mulch. If it beads off and runs toward the paths, it doesn't benefit the plants as well as a mulch that does not have that effect. If you aren't experiencing it... good. However, it's not a myth, it's what can happen.

Why does it happen? Because grasses create wax on their blades. It is called epicuticular wax, and it helps the plant conserve water.

When the grass mats, until that wax breaks down, it causes water to bead off the leaf blades.

It is not a myth. As for seeing it firsthand, I don't know what to tell you... perhaps you have a different type grass.

Oh... and wood used on the surface does not effect nitrogen at root level.

Wood at root level does not 'deplete' nitrogen. What happens is that fungi, bacteria, and other soil flora and fauna use the available N in their bodies. As they die, the N is slowly released when their bodies decompose. Any biological entity can then make use of that available N (different species can more effectively use N in different forms.) It can impede a plant's ability to make use of available N because of the competition with that soil biome. However, adding a little available N can help alleviate the problem, and in the long-run, once that soil life has done it's job and decomposed the wood, the N is now in a slow-release state for future plant use.

So... adding organic matter (including wood) can, in the short term (depending on the mass, and the environmental conditions, as well as the composition of the OM) cause competition for the available N. In the long term, the structure, and the nutrient profile of the soil is improved.

"When the grass mats, until that wax breaks down, it causes water to bead off the leaf blades."

OK, so in a 4' x 20' raised bed, where is said beaded roll-off water going to go?

Even now, as I water my beds, I see nothing but active sinking in of the water. Next time it rains, I will go out and see what happens. I have a bed that received clippings 2 months ago and is very dry. I watered it both as a shower and as misting., and no roll off. There is no significant difference for my grass from any other' lawn.

In my 50 years of gardening, I have never seen any roll-off. If I missed this, then I still wonder how far it could actually roll? Does it puddle and stay on top?

Do you have any pictures of this?

Sorry... I when I noticed that the water wasn't soaking through to the soil around the plants, and instead was working its way towards the paths, I didn't think to photo-document evidence for future reference lol. Instead, I just changed my tactics to something that worked much better for my needs.

Like I said, if what you are doing works for you, and the mulch is doing what a mulch should do to your satisfaction, then don't change. I wasn't happy, so I changed. The mulches I use now work much better for my methods.

I don't mow my yard at all, but when I collect clippings from my neighbors, I mix them into my homemade hay as mulch - if I need to - and mix the rest with leaves and wood chips on a compost pile.

Any idea how old/deep the clippings were?
I would like to imitate the situation.

It has been a number of years, but I'd guess it was anywhere between 2" - 8", and I suppose it would have been fairly fresh grass - but it had to be raked up, so I'm sure it was a mix of dry and green.

I hesitate to get into this grass clipping debate, but I will just add that it may have something to do with the type and length of grass clippings. For example, I have a coarse fescue with thick blades up to 1/4" wide. Those clippings may behave a bit differently from, say, Kentucky bluegrass, in terms of matting, waxiness, or whatever. This could explain differing results. On top of humidity, rainfall, temperature etc. Plenty of variables that could lead to different results in different places.

Unforeseen circumstances...

I have a lot of clippings, 1" - 2" with the occasional 3" clumps. It has been raining so much lately that it looks as if it will rot. I believe we have averaged 1 1/2" to 2" a week all spring.

emerogork, do you have a picture? You're saying that the grass clippings look like they are 'rotting'? I don't think it will hurt anything. You'll probably get an influx of pill bugs, but they should only go after the rotting stuff. Are you going to put a bit more fresh clippings over top?

No, no more clippings. I am sure the gardens have enough. The lawn wants them now.

Pill bugs (crustaceans) are an interesting. There are many more citations on the 'net to kill them off than ones that describe their benefits. Right now, I will take a wait-and-see mode before I think about attacking them.

I do have one, out of six, pepper plants where all the leaves have been shorn off. It is one of two nursery plants new this year. I wonder what caused it but maybe that is fodder for a new topic.

No pictures at the moment....