Low-cost compost for allBy Caleb Garvin (cgarvin)
January 7, 2009
Making compost is easy to do; in fact nature does it with no help from us. Just take a stroll in a forest near you, and no doubt you'll notice the beautiful soil structure, where the top few inches are amazing, light, fluffy, and give off a wonderful earthy smell. This is all accomplished with a very thin layer of compost, made by nature from dropped leaves, needles, other decaying matter.
So what is this magical black gold? Compost is organic matter that has been decayed and broken down by bacteria, fungus and molds. However there can be a huge difference between types of compost. Most compost is made with equal parts brown and green matter, something like a bag of grass clippings and a bag of fir needles mixed together and left to break down will make about a gallon bucket of finished compost.
My problem was that I didn't have enough brown and green matter to even come close to the amount of compost I use. Hence I bought from the stores for awhile, usually steer compost for about $1 a bag. That got expensive quickly so I found a local bark and gravel place that makes compost from tree trimmings and grass clippings. They sell theirs for $10 a yard, more affordable yet still expensive, especially when it costs $20 to drive to the store. So I kept looking and I found the mother lode of black gold: a horse barn 4 miles down the road had over 100 yards of composted manure piled up around the property. And guess how much? Oh yes it was freeeeee, those of you who have read my previous articles know how I love free. Yes I can already hear the naysayers complaining about the poor quality of horse compost. Yes I am aware of the problems with horse compost, such as weeds, and the fact that most horse barns use cedar shavings in the stalls. The cedar shavings have a chemical that inhibits the growth of nearby plants much like walnuts do. But what if they are fir shavings?
This makes a world of difference. Not only do fir shavings decay much faster than cedar shavings, but they have no growth inhibitors. If your horse barn uses cedar, ask them to try out fir shavings. Fir shavings are cheaper and the end result is much easier to get rid of. And what about the weeds? Just let your compost pile sit longer than usual. I'm fortunate to have a tractor with a front loader so it is easy to roll the pile every couple weeks; the seeds that surface will sprout then get rolled back into the pile. That combined with the fact that the compost is so rich it kills off most sprouts and you now have very cheap good quality compost. I managed to bring home 52 yards last spring with 1 tank of diesel; my average cost was $2 a yard. I use it instead of bark to mulch my flowerbeds, till it into the garden to soften the soil, and as a portion of my potting mixes. I even spread it on the yard instead of fertilizer.
A cautionary note on horse manure: a recent issue of Mother Earth News contained an article entitled "Watch out for killer compost." The article warnsa about a new herbicide released by Dow Chemical called aminopyralid marketed to horse and cattle ranches that takes up to two years to break down in the soil. This chemical is able to pass through an animal and the composting process, and still kill your plants. So make sure your manure source hasn't been sprayed with Confront, Milestone, or Forefront.
No horse barns close by, you say? There are more options.
- Let your local landscapers know and they can drop off grass and shrub clippings; utility companies will drop off chips if they are in the area. Every fall in our town, the city lets everyone put fall leaves on the curb for pickup, so pick ‘em up. I like to get a truckload of maple leaves to spread out in the garden to keep the weeds down for winter. You can even ask your neighbors for grass clippings, but consider their chemical fertilizer use since many fertilizers contain weed killers and bug killers mixed in; you don't want those in your garden.
- Some municipalities have a compost program where all the leaves and brush picked up in the fall are taken to a collection site, shredded and composted. After it's done composting, they give it away for free, or for a small fee. If your city doesn't have a composting program available, you could try to get them to implement a composting program.
- Any coffee shop worth its salt uses a 5-gallon bucket or more of coffee a day, after they're done with it they give away the grounds, which make great compost. Just get a few buckets with lids and offer to pick them up every couple days. They add up quickly, and smell wonderful.
- Most towns have a barbershop; all the hair trimmings can be yours for free and makes great compost as well.
- If you live near the beach, seaweed makes very good compost complete with every micronutrient your plants need; just rinse off the excess salt. Also near the coast are fish cleaning stations with plenty of guts, heads and skins for free. Go slow with animal parts or you'll have every dog and cat for miles turning your compost pile for you.
- Cabinet shops and custom wood shops usually have lots of sawdust free for the taking, just be sure they aren't cedar or walnut (both contain growth inhibiting chemicals).
- Local nurseries often have a large trash pile of plants complete with soil free for the taking, but be sure to ask permission and let them know you want it for your compost pile. Some nurseries will not let you have them, as they think any plant you get for free you won't buy from them. I have managed to save a few specimens from the compost pile, but usually they are there for a reason. My favorite is a hart's tongue fern that came back very nicely from near death once planted in a nice shady damp spot.
We have a large nursery just down the road that grows trees for transplanting in logged areas and they give away tons of free dirt knocked from the roots before they ship them.
- Moldy hay is often available in spring and once composted is nearly weed free and easy to handle, but you should wear a mask so as to not to breathe the mold spores.
- Newspaper and cardboard in small portions also work well as carbon sources (brown material).
- If you heat with wood, save your ashes to spread in the garden and mix into your compost pile. Remember to use sparingly, similar to spreading lime on your garden.
- Free scraps of wallboard are available at most construction sites; just break into small pieces and toss in the compost bin or till into the garden. An easy way to remove the paper backing is to throw the scraps in a bucket of water for a few minutes and the paper peels right off; and some of the newer wallboard has no paper. Gypsum is the mineral inside drywall and is mostly calcium, but it doesn't raise pH levels as lime would.
For an easy compost bin, all you need is four wood pallets. Screw them together to make a box and fill with your free materials. Make sure you alternate green and brown ingredients in 3- to 6-inch layers until it's full. Throw some high nitrogen fertilizer on top (or hot manure), wet it thoroughly, and in about two months you will have about one-third of a cubic yard of finished compost.
Here is a partial list of compost ingredients and the approximate percentage of nutrients in each.
Dry animal manure
Dry chicken manure
Raw bone meal
Processed bone meal
Feathers / hair
Sulphate of ammonia
Sodium nitrate guano
Sulphate of potash
Muriate of potash
I included some chemical fertilizers in this chart; sometimes your compost will need a little extra boost. As you can see from the percentages, it doesn't take much. A handful or two will do in most cases. Most materials for compost have low nutrient levels and depending on the mix you may want to bring up one of the levels a bit.
To create a balanced compost you will want to include trace elements. These are available as "fritted trace elements" at most farm stores; around 2% by weight can be added to your finished compost. You also want to add about 2 cups of dolomite limestone and 1 cup of rock phosphate per yard of raw compost.
Vermicompost (aka worm poo) is produced by worms. The beauty of this is that the worms are very quick to reduce fresh green matter into vermicompost. You can find easy to build plans for a worm bin at this website. This bin consists of some storage totes with holes drilled thru them, into which you put in some worms and some fresh green stuff like manure, grass clippings, and the veggies off your kids' plates. You can also use coffee grounds, shredded newspaper and straw or hay in limited amounts.
The main difference between vermicomposting and regular composting is that you don't have to do it all at once; you can add a few inches of organic matter to the worm bin each week and the worms will move from the stuff they've eaten already into the new food. After your bin is full, simply put some fresh food in on top to entice the worms to move to the surface then shovel the top layer into a bucket or extra bin. Once the majority of worms have been moved, you can put the rest of your fresh worm castings into a bucket or trash can for storage. Then start the worm bin from the bottom up with the layer you pulled from the top.After telling you how to make compost or find it for free, I thought I should warn you about some common mistakes. Even though compost is natural it can burn your plants, I've made this mistake many times. I get carried away using it instead of bark mulch and have burned several plants and killed a few outright. Usually this happens when I put down a 4-inch layer on an existing flower bed, it kills off the weeds and occasionally my plants. To be safe, keep your applications to an inch or less.
I've also made the mistake of over-fortifying my planting holes with compost. A better practice is to mix in a handful of compost in the backfill dirt, then wait for the plant to establish before adding anymore compost. A few exceptions are heavy feeders such as rhubarb and asparagus which love compost. Grapes do not like any compost mixed in the hole and should only be mulched with a small amount. As for an easy way to test your compost is, to plant a couple bean seeds (which will sprout in days.) If they burn, the compost is still too hot for heavy applications. Just mix in some dirt or apply less.
I hope this article gives you some ideas on where to locate compost and compost materials for your garden. Now get composting!
 Nutrient values in the table courtesy of "The Bio-Gardener's Bible", by Lee Fryer