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By: Jeff Dadisman, Upper School Teacher // MDS Musings Blog

If you’ve never considered how nature recycles organic material back into rich soil that improves plant growth and subsequently entire ecosystems, hopefully this post is a stepping-stone towards understanding this principle.

In nature, humus (hyoo-muh s) (not to be confused with hummus, the delicious Middle Eastern dip) is the top layer of a soil profile made up of organic material (fallen leaves, dead wood, fallen fruit, carcasses, animal droppings, etc.) at various stages of decomposition.  Humus is highly influential in the health of a soil and the soil’s capacity to ‘feed’ plants.  It is a major source of plant nutrients, a vital habitat for critters that aerate the soil, and it expedites nutrient cycling. Also, soils with a good humus layer have much higher moisture retention during drought conditions.

This is where the practice of composting comes in and why it is important for general landscape health and performance.  Composting is a human practice for creating humus with organic materials that flow into and out of our own physical space- at home, work, school, and farms.  An annual top-dressing of an inch or two of finished compost onto a garden bed, crop plot, or around the root zone of shrubs greatly improves overall health and performance of the plants.  Additionally, the biological activity that accompanies this new soil habitat can improve the entire soil profile.

Here is a quick-list of rules and tips to become an effective composter!

What to collect (in the kitchen): Fruit and vegetable scraps including green leaves, fruit cores, fruit rinds, vegetable skins, discarded seeds, etc.  Coffee grounds, spent brewing grains and hops, and eggshells are excellent.  Repurpose a Tupperware container with a lid with some pinholes or you can purchase a specialized anti-odor kitchen compost collector.

What to collect (from the yard): Raked leaves (preferably from turf areas).  This material will almost always also contain smaller twigs and spent reproductive parts such as Pine cones and Sweetgum balls.  It’s ok to have some of this coarser material, as long as the majority of the ‘from the yard’ material is leaves.  *To keep a good compost operation going throughout the summer, pick up bagged leaves and grass trimmings (there is typically an abundance in the fall and spring) on curbsides.  Build up a stock-pile for when leaves become scarce in the summer.

Getting the mix right: You must stay within a certain ratio of “browns to greens” or “carbon to nitrogen”.  “Browns” are less nutrient rich and are the fallen leaves, twigs, Pine cones, and Sweetgum balls, and they contain significantly more carbon than any other element.  “Greens” are the kitchen scraps, and they have a much higher amount of nutrients.  The correct ratio range of “browns to greens” or “carbon to nitrogen” is 30:1 to 50:1.  30:1 is the richest you should go with your mix, and anything over 50:1 takes a long time to decompose into a finished compost.  *There’s no standard way to figure out your ratio.  It’s done largely by eye-balling the mixture and good ole’ trial and error.

Where & how to mix: The three main options are passive compost piles, compost bins, and compost tumblers.  They all have their pros and cons based on price, space, amount of compost material, and desired decomposition rate.  The MDS Garden uses two 80 gallon compost tumblers, and we’ve produced eight tumbler loads of finished compost in under a year.  Click here for some ideas. *Flipping and aerating the pile periodically is key!  At home, I’ve always used the passive compost pile method, where I flip the pile with a pitchfork every two weeks.  The tumblers spin along a perforated axel rod, which increases aeration and makes flipping quite easy.  Having really large piles is fine, but having access to a front-end loader may be necessary for flipping.


  • Miscellaneous tips and info.
    • During significantly hot and/or dry periods, it is good to water your compost.
    • Introducing earthworms (just go to a live bait store) can greatly expedite the composting process and give you a richer finished product.
    • Starbucks and local breweries often give away spent organic material for composting.
    • LEAVES AREN’T TRASH!  Although composters can benefit from collecting bagged leaves and yard debris, people should reconsider this wasteful exercise as it severely depletes the soil and produces a lot of plastic waste.
    • Many gardeners get as much enjoyment from tending to their compost as tending to their plants…watch out, you could become a dirt-nerd too.

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