Autumn Leaves into Cold Compost

  • Post published:10/30/2016
  • Post comments:9 Comments
2015 leaves spending the year composting
2015 leaves spending the year composting

Autumn leaves are falling. It is time to turn those leaves into ‘black gold’ known as cold compost, and improving our soil.

It was not very long into my Heath gardening career that I met Larry Lightner of Northfield. By the time I met him he was retired from the Mt.Hermon school where he had worked with students to create and maintain some of the school gardens. He still had his own productive gardens and had produce to share. He also had skills to teach and share. Lightner was a promoter of ‘cold compost.’ Most of us know that when we make a compost pile it should be comprised of green and brown materials that will eventually heat up and decompose.

Hot compost is the standard way we all learn about compost. Lightner made good use of the wealth of autumn leaves to make cold compost. He made wire fencing frames of many heights and depths and sizes. Many of his cold compost frames were circular and about two or three feet or so high. Into those frames he packed his leaves. It is amazing how quickly fall leaves break down, and how many leaves can be added over time to such a frame.

Lightner said his cold compost piles could be made high enough to act as a big raised bed making gardening easier for those who had trouble getting down on their knees. My first cold compost piles in Heath were set up inside the stone barn foundation after the barn itself burned down in 1990. After the fire the debris had to be bulldozed and carried away.  The soil such as it was, was not what anyone would call good garden soil. Nothing would grow in it.

The answer was to fill the space by creating a series of wire fencing frames about two feet high and filling them with leaves, packing them down until the frame was filled. I made many trips to Greenfield collecting the bagged leaves that many people left by the side of the street. In the spring I made small indentations in the packed leaves, filled that space with a quart or so of soil and then planted vegetable starts. The important thing to remember about these planting beds is that they did need consistent watering. Rotting leaves do not hold water the same way that good soil does.

By using cold compost planting beds for four years, I actually built up soil that would grow plants, and the frames were put aside.

Last fall we had no need of begging for bags of autumn leaves. Our Greenfield garden was full of leaves. We still had some wire fencing and built a five foot high ring about four feet in diameter. All fall we dumped our raked leaves into that frame, packing them down harder and harder as the pile got deeper.

Releasing the cold compost
Releasing the cold compost

Last weekend we asked our good neighbors, Andrew and Ritchey to help us lift the frame and release the cold compost for us to spread on our garden. Then we would be able to start filling the frame again with this year’s crop.

Ritchey’s parents, Mike and Susan Ritchey, were visiting and on hand to photograph our efforts. We brushed aside the outside leaves, and everyone was amazed to see the beautiful black gold compost that filled the frame. What a lesson about the riches of a new fall harvest.

The cold compost looked finished, but alas, the center of the pile was only partially decomposed
The cold compost looked finished, but alas, the center of the pile was only partially decomposed

However, after Henry and I were left alone to spread the cold compost we realized that the pile had not decomposed fully all the way through. It turns out that even cold compost does need air and more water than our pile got, to decompose thoroughly. We had done a really good job of packing those leaves down hard. No air and very little water made it to the very center of the pile.

We spread the compost and rotting leaves anyway, wetting everything down. I also sprinkled a little soil and mulch over the less composted leaves. The soil will be richer for it in the spring.

Leaves can also be ground up with a mechanical leaf shredder, or you can run your lawn mower over leaf piles. The shredded leaves can be spread over the gardens as mulch and will almost have disappeared by springtime. However leaves are  handled, they return organic material and nutrients to the soil. Don’t miss this chance to enrich your soil.

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This Post Has 9 Comments

  1. Helen Opie

    I find that leaving the heap for longer, 2 years. Gives a good layer of black soil. I set seedlings into the soil below the mulch in season one and sow fine seeds in year two. Also if i spread the still-dry leaves first and the more broken-down stuff on top and let winter’s rains and snows wet it down, then there is a lovely deep layer for carrots. I have very heavy clayey soil in a very eet area. Where I plant at vround level, the soil is ot workable until almost July. OK for fall crops but not much else.

  2. hairytoegardener

    I love cold composting. It makes a lot of sense. I end up scavenging from the bottom of the compost pile for the finished product. Glad you like leaves as much as I do!

  3. Helen Opie

    Not sure how to measure love of any sort. What i am regretting is no longer having a trailer to leave the guy who has a leaf raking service. He shredded them right into my to take up less space so i got about 1/4 cord of shredded leaves to lay on all mu box beds.

    When i lived in Kennebunkport a leaf-raker dumped them about 18″ deep all over my 25×100 ft garden. I just moved a flag to indicate where to dump next. The a man with a huge tiller on his full-size tractor came and tilled them in. I had 11% organic matter in that garden. Plants rose up in joy for being there. As the tillerman said when i paid him, “Them leaves won’t hurt you garden one bit.” I miss that garden!

  4. bittenbyknittin

    Interesting. I call this “slow composting” – make a pile of organic stuff and let it rot in its own good time. I heap my raised beds with organic stuff, too – wood shavings and horse manure, leaves, grass clippings, etc. – and compost in place.

  5. Helen Opie

    Mini-sheet composting!

  6. Pat

    Helen – I probably learned more about composting and garden techniques from you than any other single gardener. And 2 years was what my neighbor said it would take to fully compost – but we thought ‘surely, not” and learned another lesson. We’ll take our time this year, and set up another big bin.
    Hairytoes – I do love leaves in all their stages. We should have a Society.
    Bitten – I had never heard the term slow composting, but it certainly is accurate. We also shred many leaves with our lawn mower and spread them on the planting beds. They are undiscoverable by spring. I was interested that our Department of Public Works had a notice in the newspaper this am, suggesting that people create a leaf composting bin in their yards, although they can also bring them to the transfer station. Do you think someone there read my column?

  7. Helen Opie

    If they themselves did not read your column this evidence that the seeds of Right Gardening (what’s right for the earth/our environment) are blowing in the wind and settling to germinate in far flung and varied places.

    And for me it all began with Ruth Stout and VT gardener of the 60s &earlier Samuel (?) Ogden.
    They showed me the viewpoint to garden from.
    I consider you part of that fine chain of garden writers.

  8. Denise

    For many years I just threw leaves in the back corner of a garden that wasn’t used for anything. When we fenced the yard I had to clean it up. This year I decided to start planting there and was amazed at the beautiful black dirt I found. Of course, those leaves had like 20+ years to decompose. I grind my teethe every year when I see a neighbor have someone haul away all her leaves and then she goes out and buys bags and bags of mulch for her yard.

  9. Helen Opie

    Hmmm. I’d be tempted to either ask her for some or ask for all so she saves the hauling fee. If there are branches in it and you have space, put them in an out-of-the-way place for a tiny wildlife shelter. If full of invasive plants, don’t compost them! I ask my neighbours for leaves because i have’t any trees and am bordered by evergreens at front boundary.

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