I have enough shredded leaves to put down a 6 inch mulch on my garden bed. I am ready to till it under for the winter. Should I till in the leaves or leave them on top of the tilled bed? And why?
I think either way would be OK. It depends on your weather.
However, many who post here will scold you for even contemplating tilling your soil.
But, I know that the November and December winds here in the Midwest heartland can be fierce. So, if the leaves are dry and not covered by snow ... the wind will blow them off your garden shredded or not. We have had blustery winds up to 30 mph here in Iowa all month and the leaves are running around like second graders at recess.
If I had 6 inches of leaves on my garden I'd till 'em in because of the wind.
I've done it both ways.
When I left them on top, in the Spring they turned out to be a wet spongy mat over the soil holding the ice and water against the soil long after the snow melted and keeping the soil frozen and wetter longer. Therefore, this method delayed planting an early crop. It really turned out to be a mess.
When I tilled them in, the veins in the leaves acted like fiber needles holding the soil together in clumps which were difficult to break up. It took 2 years for those veins to fully break down and release the clumps.
On the third year, I composted all the shredded leaves in a 8x4 bin, with nothing else included, except some lime. It took about 2 years for the leaves to full break down but when they did, it was like the texture of coffee grounds. It was much better this way and more uses for it. But I had a lot of room and did not mind using the space for the bin. Maybe tomorrow I will post a pic of the leaves in the bin.
Unless you really badly need to till that organic matter into your soil (Most of Illinois is clay) you will be much further ahead using them as mulch on the beds. As the soil temperature cools down now the soil bacteria slow down and they may not get all those leaves digested by next planting season and that could cause a short term Nitrogen deficiency in your soil when they do get busy next spring and digest those leaves. Unless you have a lot more leaves readily available for next summer what will you have for mulch to help conserve soil moisture then, if next summer is as dry or drier than this past summer.
So you have gotten some reasons for and against tilling and some even against both.
If no one can give you enough reasons either way, perhaps you might leave one part of the garden as is with the leaves on top as mulch and then go ahead and till another part of the garden so you can see what sort of effect the different methods have in your climate and on your particular soil. Then share!
I wish I had enough leaves to cover everything with 6". I don't think I would till myself. Partly because I don't own a tiller and partly because my sand needs a covering of mulch more than it needs the leaves mixed in. My climate also decomposes things quickly.
Thanks for all of the advice. After considering the wind, my penchant for planting early spinach, and the unmistakeable preference of the missus, I tilled the shredded leaves in. It rained 1/2" the next day, so everything is fluffy and beautiful.
I think that tilling previously shredded leaves will accelerate decomposition so I am not worried about locking up nitrogen next spring. My interest in laying them as a mulch ws to see if doing that would facilitate more earthworms.
THanks to all.
Tilling leaves, shredded or whole, into the soil will result in them being digested much faster. I found many years ago that in my sand tilling large volumes of leaves into the soil got them digested in under a year and they were digested so fast and completely that there was not residual organic matter, humus, left. I saw that the humus level in the perennial beds, which were never tilled, increased year by year and it dawned on me that tilling organic matter into soil is counterproductive, it is a lot of work and does nothing to increase the humus level while plunking those same leaves down on top of the soil (most soils anyway) will allow the soil bacteria to move them intothe soil and increase the humus level and I do not need to work very hard to accomplish that.
If left untilled and whole,is there any way to increase the rate of decomposition...by adding Peat moss/soemthing liek that...
We created a lot of leaf mold by filling plastic trash bags with shredded leaves, then moistening them and letting them sit over the winter. It makes fabulous mulch in Spring and was actually so friable by then that it was easy to work into the soil with a digging fork. Cheryl
Peat moss is a high carbon material with no nutrients to temp the soil bacteria that will digest it. If any peat moss is put into soil and you want the soil bacteria to digest that you need to add something with nutrients, compost, manure, some kind of fertilizer, something.
Leaves have a C:N ratio of between 40:1 to 80:1 almost close enough to get digested with out any additional source of nutrients and certainly not peat moss. Mixing in some manure, or other source of Nitrogen, could aid in speeding up that digestion.
kimmsr confuses me-- first suggests that tilled leaves would not break down by next planting season and lock up nitrogen, then suggests that tilling them in would break down so fast that there would be no residual increase in humus. Dude--where's my organic matter???????
In or on the ground, I'd mix in some greens such as chopped veg scraps. I did that last year and it made fantastic compost/mulch. I personally would rather compost a pile made that way and mulch with chopped straw, which breaks down faster and doesn't clump.
Last fall, I piled some leaves on the garden for lack of a better idea of where to put them. I also added some partially completed compost. In the spring, what had been 3 feet deep was about 6 inches deep.
If my results are representative, you'll end up with an inch of mulch.
If I were you, I'd leave the 6 inches of leaves on the surface. But I'm lazy enough that I left 3 feet of leaves on the surface.
3 feet of leaves? Wow.
So, where do we stand here?
If we have enough heat before the freezing temps hit, Till?
If not, then Mulch?
Yep, I'm a bit confused too.
I still say tilling in the leaves and clippings wouldn't hurt and should help.
Anytime you till organic matter in to soil you could get the soil bacteria working hard at digesting that organic matter, and in my experience that can result in the organic matter being well digested and no residual left, humus, in the soil. Organic matter put on to soil as a mulch will not get digested that fast and will be there much longer and will not cause the soil bacteria to digest it all that well and that will leave some residual, humus, in your soil. Just how quickly will depend on where your soil, and the Soil food Web, is. A good healthy soil will be different then would be a soil that is not good and healthy. So if you till organic matter into your soil and it is still there several months later that should be an indication that your soil is not as good and healthy as it could be.