(Photos:  Variety of Composters)

Composting

Outdoor home composting harnesses nature’s activities to produce readily available, low-cost, mostly organic, home grown soil amendment and garden fertilizer for all gardens from recycled raw kitchen and garden waste! Composting reduces curbside waste, and saves money since homegrown compost quietly “cooks” in your yard and will nourish all soils, improve soil structure, retain moisture, balance pH, fight diseases,  such as corn, soy beans, papaya,and feed worms. Also, if handled properly, a backyard composter will not smell.

Compost Terms

  • “Readily available” — compost is on hand when you need it.  It is composed of fresh fruit and vegetable kitchen waste; potting soil; and disease-free garden waste: vines, leaves, roots, and seedless weeds, all from your kitchen and home garden and composted in a backyard or on a balcony.
  • “Low cost” — the initial compost container purchase and then your time and effort for the years to follow.
  • “Mostly Organic” is the one drawback as home-grown compost will not be 100% organic. Unless you shop only for organic fruit and vegetables and you garden organically, there will be some small amount of chemical residue getting into your compost (e.g., insecticides and/or fungicides in the wax on some non-organic fruit, chemical sprays on various non-organic vegetables, some systemic chemicals, and possibly some GMO/GEO products such as corn, rice, soybean, papaya, …).
  • “Soil Amendment” – compost will loosen stiff soils (e.g., heavy clay) to improve soil structure for air and water penetration. Without air at the roots, plants may drown in the resulting swamp.
  • “Fertilizer” – Compost stores a large variety of nutrients (N. P. K. + trace minerals) and will nourish soil in all gardens: flowers, shrubs, herbs, and vegetables. While nitrogen (N), phosphorus (P), and potassium (K) are very important for plant health, so are a multitude of trace elements such as zinc, calcium, magnesium, and sulfur to name only a few. Compost has it all.  Although compost NPK numbers are low, compost continues to give day after day as a slow-release, non-burning soil nourishment.  Best of all, you can compost year-round and you control the composition!

Composters come in all sizes, shapes and prices

In composting, you want to control the composition, the access (your access to load, aerate, and unload, and to keep out wild things), the mixture of ingredients, as well as the heat, air, and moisture. A covered container helps you do this. The most effective and convenient urban composter is a black plastic rectangle with the sleeve top cover containing two flip top doors, no bottom (allows nature’s decomposing agents to enter), and a bottom exit door to access the finished compost.

The container will keep out the rain and the wind as well as all critters except raccoons, and for these, you need bungee cords or locking lids. However, rodents are common in compost and if you wish to keep them out, you need a composter with a closed base (e.g., metal plate, hardware cloth, patio stone, …).

Technically, a composter should be filled to the top and allowed to “cook” while you aerate (stir) the pile and check periodically for heat, air, and moisture.  This is necessary so you can make any needed adjustments.

Some books will tell you to layer the compost ingredients, but for most urban gardeners this is not at all practical. Besides, the necessary aerating stirs the pile and destroys the layers.

Recommended Ingredients for Kitchen-fed Composters

Shredded Browns (carbon) – egg cartons, dried leaves (small amount each time), unmarked cardboard, brown paper, newsprint (no gloss or dyes), nut shells, tea leaves & bags, coffee grounds & unbleached filters, straw (small amounts).  Aerate each time you add a large amount to the composter.

Chopped Greens (nitrogen) – raw vegetable, fruit (limited citrus) and flowers, seed-free weeds, fresh grass clippings (modest amounts at any one time), garden clean-up waste (NB fresh greens also add water to the composter).

Others:  Dry, crushed egg shells (calcium) – slow to break down and may appear unsightly but good addition – e.g. blossom end-rot in tomatoes and peppers results from inadequate moisture and insufficient calcium.  Tip:  you may wish to keep these aside to used as a slug/snail barrier around affected plants.  Left over cooked food that has not been salted, buttered, or oiled as well as the plain water they boiled in (e.g., asparagus, Brussels sprouts, carrots…) can be added to the compost.

Compost activators – Garden soil (1 shovel full from time to time adds bacteria, fungi, insects, and microbes; especially good to cover fresh fruit and reduce the number of flies), old compost, comfrey leaves, stinging nettles, or chicken manure.

Tip: consider washing chemicals off non-organic fruit and vegetables before peeling to reduce waxes and sprays containing insecticides, fungicides, and anti-bacterial chemicals.

Do not include

  • Animal products (meat, bone, gristle, fat, grease, lard, butter, skin, giblets, feces (poop), cheese, treated fur/hair, fish) – these need a very hot compost pile to break down safely as they contain harmful bacteria and attract rodents. Green bin this waste.
  • Cooked food and table scraps that are salted or coated in butter/margarine/oil – (attracts rodents).
  • Weeds or grass with seeds (seeds last a long time and will germinate after compost is used).
  • Diseased plants.
  • Paper that is glossy, bleached, or coloured with inks or dyes.
  • Saw dust from treated wood (e.g. decks and fences of treated wood may contain arsenic or copper sulfate which will leach out over time).
  • Wood ash tainted by paint, varnish, creosote, fire starter or fire retardant chemicals, or contaminated ground soil.
  • Invasive plants (like mint, dog strangling vine, or bindweed).
  • Any material of which you are in doubt about the chemical contents.

Basic composting is simple: combine chopped greens and shredded browns with a shovel full of garden soil and aerate from time to time. Be cautious with items deemed “biodegradable.” Many items are biodegradable but some take years to decompose (e.g., soft parts of plants take a short time; twigs & woody bits take a long time, and some items (chunks of wood) can take years).

Tools & Conveniences

  • A compost aerator to stir the pile.  A 3-ft. long green steel bar with folding wings at the bottom and a “T” handle is recommended. My first 3 aerators were too short to reach bottom, and quickly broke or rusted.
  • Kitchen collector pail options:
    – stainless steel pail with lid (recommended – no smell, no filters to buy, easy to clean, and does not stain!)
    – porcelain container + ventilated lid + charcoal filter
    – plastic container + ventilated lid + charcoal filter
  • Spatula to scrape kitchen collector pail into composters.
  • Compost knife to chop material into easily biodegradable chunks.
  • Compost shovel to access compost (size must suit the composter escape hatch).
  • A soil rake to sort unfinished material in the compost or a compost screen (metal screen with 1/2 inch squares called  “hardward cloth” recommended) to sift out the unfinished material.
  • Garden trug, wheelbarrow, or pail to transport the finished compost.  A flat bottom shopping bin or an old tarpaulin can be dragged to where you want it.

Aerating compost will mix or stir the ingredients to redistribute the air, moisture, bacteria, fungus, and insects. It also discourages wasps and rodents

from nesting inside the composter, and reduces (somewhat) the cloud of flies. I aerate the piles whenever they need water and air. No aeration composting can take up to 2 yrs.

  • Aerate once a week – compost in 3 to 4 months
  • Aerate Once a month – compost in 1 year
  • No aeration – compost in approximately 2 years (and possible bad smell if anaerobic).

(Photo:  compost aerator)

Note: Kitchen-fed composting differs from community garden composting. The production of useable compost is affected by the pile composition and the mixture of ingredients: woody stalks (as in chopped sunflower stalks, brassicas stocks, and tomato/squash vines), greens, browns, and garden soil. Loads of one type of material (e.g. sod, leaves, vines) will take a long time but kitchen fruit and vegetable cuttings with egg cartons, clean cardboard, and garden soil/old compost will be ready in a shorter time.

Community Gardens need large compost bins for the boom and bust flow of compostable material.  Three bins or more of cubic yard dimensions (3’x3’x3′) would be ideal. Fill them one at a time and aerate regularly with a compost fork — especially when new mterial is added.

Some communty gardens resort to compost piles — these are not recommended as they are too hard to manage.  They get far too large and they cannot be aerated or closed off to allow them to work.  Making adjustments is well nigh impossible.

In the fall, at cleanup time, all gardeners should cut and drop the soft parts of plants on top of the soil to act as a mulch, to suppress weeds, to reduce erosion, and to relieve some of the congestion at the composters. Nature will look after the plants an in spring most will have returned to the soil as fertilizer.  Woody bits (stalks and vines) chopped up can be added to the composters or buried under ground in a trench at the edge of plots.

Compost Problems

  • Too wet = slimy anaerobic decomposition, very smelly – add dry browns & aerate
  • Too dry = low moisture discourages beneficial agents* – add water &/or wet greens
  • Too little air due to compaction stalls decomposition – aerate
  • Too much air, pile cools & decomposition slows – reduce air with a windbreak
  • Too little heat (pile too small) composting slows down – add material & aerate
  • Too much heat (pile too large) kills beneficial agents* – reduce pile & aerate
  • Too acidic (citrus, pine needles) hurts beneficial agents – add a small amount of agri. lime
  • Wasps attracted to fruit sugars – aerate, cover fruit cuttings with soil, or use a waspinator**.
  • Fly swarms – aerate or cover new additions with old compost or garden soil.
  • Racoons – lock, bungee cord, or tie down lids
  • Rodents – remove bird feeders and pet food, enclose composter bases with “hardware cloth” or a patio stone bottom.   Chicken wire is not recommended as the holes are too big and some chicken wire is too low grade and not strong enough.  Snap traps baited with peanutbutter can also be used, but beware that snap traps are not particular about what they kill — protect traps from access by other creatures or you may regret what you trap!

Notes: *“Beneficial agents” are microbes, bacteria, fungus, and insects (e.g. earwigs, centipedes, sow bugs)

** “Waspinator” – wasps are territorial; an artificial wasp nest will discourage interlopers. Purchase one, or fill a brown paper bag with newspaper, shape it like a nest with the bunched end down and hang it near the composters. Wasps will avoid the area.  Check the paper bag after a rain.

(Photo; purchased waspinator)

Notes

  • Locating your composter: place it where you have easy access for loading and unloading. If possible, shelter it partially from sun and wind, and beware of tree and shrub roots – these roots will feast on your rich compost.  Also do not hide it — rodents love the privacy.
  • Insects (e.g. earwigs, sow bugs) help decomposition but locate composter away from the vegetables as earwigs will travel to your garden and eat entire rows of young vegetables like beans and Asian greens.
  • If you have more than one composter, fill them one at a time and compost all year. Moist wood swells and rots, so if you are going to build your own, Eastern white cedar or Hemlock last longest (15-20 yrs.).
  • Treated wood leaches arsenic or copper sulfate (decks, sheds, wood fences, etc.).  Do not use it.
  • Avoid using carpet as a compost cover or weed suppressor (chemicals leech out and industrial bits will discintegrate into your soil).
  • Compost tea – put compost and water in a bucket for a few days, strain the tea, dilute it (10 water:1 tea) and use it to fertilize containers.

To use your compost, you can scoop out small amounts from the bottom escape hatch and add compost to both plots and containers. If you want to use it all, remember that not all materials decompose at the same rate. You will have to rake or screen out out the unfinished material and put it back into the composter.  “Hardware cloth” – actually a metal screen —  with 1/2 inch holes makes the perfect screen.

(Photo:  screening compost with a “Hardware Cloth” cylinder)

Tip: lift the entire composter off the pile and rake the contents all to one side (on a tarp if necessary). Replace the composter, rake out the unfinished bits, and replace them in the composter at the bottom.  Screening compost is slower but is better than raking a pile of compost and recycling the unfinished bits.  Then, distribute the finished compost.

Bonus: plants can grow from the composter – tomatoes, potatoes, squash, melons – to decorate your pile, enlarge your harvest, and provide a compost water meter (the leaves of these plants will droop if there is insufficient moisture). When this happens, add water or rinse your kitchen pail with rain-barrel water and add the rinse to the composter.

Happy Composting