Gardeners Often Ask How To Source Organic Matter For Composting In Gardens Or Allotments. In this Article I Explain Where To Source Quantities of Organic Material.
Garden soils need plenty of organic material so that it can feed the plants we grow and harvest. But many people find it difficult to find enough organic material for the size of plot they have. There are two or three ways to improve the situation. Grow your own organic matter or source it from outside your garden or allotment plot.
Traditionally this often meant making compost heaps or sourcing things such as farmyard manure from local farms. These would then be dug in to the soil in spring after having been spread omn the soil surface in autumn or early winter.
An Easier Way To Grow Crops?
The advent of No Dig meant that the composted material was put on the soil surface and left without digging. That sounds much easier but some gardeners believe that compost must be dug in and don’t believe good crops can be produced unless they’ve broken sweat when digging in copious quantities of compost. Other claim that though they want to go No Dig they cannot make enough compost or afford to buy enough compost to make no dig financially viable. Personally I think they are missing the point as No Dig requires no more compost on the surface than many gardeners dig in!
A last thought on the quantities of compost/manure needed in either system. If you are able to grow crops more intensively then you need a smaller area that needs compost. Many allotments I see grow extensively rather than intensively. They have big plots that are often devoid on plants as they are fallow or sheeted down for winter. In my view, based on decades of market gardening and gardening, this is the wrong approach. The harder your land works for you the more productive it becomes. Soil actually thrives on having lots of plants growing in it.
What is Organic Matter?
As the two quotes below indicate organic matter is derived from living material.
‘Organic’ means derived from living matter.RHS
Organic matter consists mainly of the living organisms in the soil (“the living”), the fresh residue (“the dead”), and the well-decomposed (or burned) material physically or chemically protected from decomposition (“the very dead”).SARE.org
When composting we often think about mixing greens and browns to make good compost. Both are derived from organic material but are in different states. Greens are normally considered to be materials that are rich in nitrogen or protein. For example freshly mown grass. They tend to heat a compost pile up because they help the microorganisms in the pile grow and multiply quickly. Browns are carbon or carbohydrate-rich materials. Examples are dead leaves, woody materials, woodchip, cardboard and paper.
Browns tend to have the following characteristics:
- They are slower than greens to decompose.
- Have relatively low nitrogen and high carbon
- They often have a very fibrous content.
- Low moisture content
- Bulky so providing air pockets in the compost.
There is a lot of advice out there that explains how you need a certain ratio of nitrogen to carbon to quickly make good compost. Whilst this is technically true it is not easy for the average gardener to determine the carbon:nitrogen ratio of their organic material so the advice I give is don’t even try. Mix what greens and browns you have and they will rot down in time. Decomposition is a natural process and isn’t driven by rules. Your organic material might take a bit longer to rot but it will eventually rot. I previously wrote about composting woodchip. It is very low nitrogen and very high carbon. It might take a couple of years to rot down properly but it will rot. I’m actually experimenting with mixing mown grass with woodchip and believe it will be quicker .. but I don’t expect miracles. It is still going to take a good while, at least a year, perhaps more.
Sources of Organic Matter For Composting
I’ve already mentioned plant material you can grow yourself. Left over plants, removed leaves, crop remnants, grass mowings. There is a considerable amount produced by most gardens each year.
Crops Grown For Composting
If you have plenty of space you can grow crops such as comfrey that can be cut and composted. It is high nitrogen and can decompose quickly. It wills act as an “activator” when mixed with other organic material. It is worth noting that garden centres often sell expensive compost activators. These are essentially high nitrogen products, sometimes with a few bacteria added, but do no more good than many things you can produce yourself!
Other crops grown for composting include lucerne, clover, fava or broad beans. Fava or broad beans ar one of my favourites as not only do they produce a lot of high quality organic material for composting but they also produce a crop of beans, if you want them, and contribute nitrogen to the soil via their roots. So leave the roots in the soil!
Maize and sweet corn are the same species and produces a lot of organic matter per unit area. Once the crop is taken you still have a lot of organic material to dispose of and it composts very well. It is quite fibrous so putting it through a chipper or running lawn mower over it will help it break down faster. Being fibrous you might classify it as a brown. But harvest it early and you have a green! The choice is yours.
Animal Based Manures
The choice of animal manure is huge. From farm animals such as cattle and pigs to horses, llamas and the manure of pets such as guinea pigs. They sometimes come as pure manure or can be based around the bedding systems employed to bed them on. Cattle manure for example is often straw bedding based and is very dense, whilst pig manure is sloppy and very smelly. I much prefer cattle over pig manure. But sometimes it is down to what is available.
Aminopyralids are a group of chemical based herbicides used to kill weeds in grass and cereal crops. They are persistent and can be found in some straw and hay remnants in manures. The contamination is often sufficient to damage crops grown in the manure or compost that is produced and can last several years before breaking down. So beware this risk and check if the supplier can give guarantees on the manure being contamination free. Should they buy in the bedding or feed materials it will be difficult for them to be sure.
Bracken is readily available in many areas and is used by some gardeners to make compost. Landowners are often very glad if someone will take it away.
Bracken can also be used in the Plaggensol systems used for bedding cattle.
Cardboard and Paper As A Source Organic Matter For Composting
Clean card and paper is woodbased and hence high fibre and carbon. Some people express concern about printing inks used and that was a legitimate concern when metal based inks were used. However, today most inks used are vegetable based as this is lower cost.
Concerns over glossy papers are also often voiced. Plastic based laminates are certainly not going to compost down so need avoiding. However most glossy papers are china clay (kaolin) based and there is no need for concern.
Cardboard and paper contaminants such as oils, paints etc are of concern and should be avoided unless it is clear the contamination is vegetable based eg olive or sunflower oils.
Pure straw is a brown so high carbon. It can be used in a compost heap or as a mulch in a Ruth Stout style garden.
Spent Mushroom Compost
I used to buy this by the lorry load when I had a market garden. The cost was just the hire of the lorry as it was seen as a waste product that mushroom growers otherwise had to pay to dispose of. Today it is seen as a valuable asset and large commercial mushroom growers sell it in bulk.
However, smaller scale mushroom producers are often glad to have someone take it away.
Seaweed: The Complete Source of Organic Matter For Composting?
I’ve written elsewhere about the Cliff Edge Plat Farmers and Growers of East Devon. This growing system lasted several centuries and the main soil feed was seaweed. If you can get clean seaweed it is an excellent material for mulching or composting. Ensure it has had a good shower of rain wash it free of salt before using it for either purpose.
Coffee Grounds & Tea Leaves
Today we seem to be a nation of coffee shops .. and this is good news if you want to make compost. Coffee shops have loads of spent coffee grounds to dispose of and that costs money. Unless someone like you or I collect them for composting. They make a good addition to compost heaps so look for a source if you can.
Provided it isn’t contaminated with coal ash or other contaminants wood ash makes a good addition to any compost heap.
Left over food (and empty cardboard boxes) make excellent composting material. Sending it to a biodigester or landfill is a waste when you can compost it yourself. The normal advice is to exclude meat from composting as it encourages rodents, however I know many people that ignore that advice and compost meats as well. You decide for yourself.
How to Compost Organic Matter
This isn’t the topic of this article but I’ve written several posts on composting, some with videos, which can be seen by clicking the following links.
Tag: Source Organic Matter For Composting
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