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How to make…compost!

Posted on 04 May 2016

This is a guest post by Rebecca Knowles, Horticulture Tutor for Groundwork MSSTT in recognition of Compost Awareness Week. 

Not much will grow in a soil without nutrients so the gardener’s mantra to fix all soil ills is simple - add organic matter! 

Most plants require a soil to be moisture absorbent yet free draining, an often confusing statement. This is always achieved by the addition of organic matter as it allows the soil to retain the nutrients and moisture needed by our plants whilst improving soil structure and the movement of water through the soil. 

A home-made compost makes the gardener an expert recycler and can reduce your carbon footprint significantly – no big trucks needed to deliver this here! For success you need only follow a few simple steps…

Step One

Allow as much space for bins as you can, 1 cubic metre is a good starting size. Site your bin in a shady spot directly on the ground to allow good migration of soil organisms, the key to decomposition.

Step Two

Get your mixture right!  The reason most compost systems fails is due to a lack of lignin, this is found in woody brown materials, pruning’s, bark chippings, straw, cardboard and the like. Aim for 50 – 75% of this kind of carbon rich material.  Green and soft nitrogenous material makes up the other 25 – 50%.  Grass clippings, annual weeds, green plant material and vegetable peelings, avoid putting potato peelings in your compost or you will get an unexpected crop of potatoes that may not be virus free! You should also avoid putting cooked food on your heap as this may attracts rats and perennial weeds as these may persist after composting.

Step Three

The mixture should be added in layers, too much green material added at once will cause the compost to become wet and slimy slowing decomposition.  If possible add all the materials in one go, this is fairly easy at the end of summer when excess plant material is abundant, but can be done at any time. Once the heap is full it should be kept moist and turned at least once a month.

Step Four

Your compost will be ready in between 6-24 months dependant on turning, temperature, materials added, moisture and whole host of other factors, should be dark brown and mostly unrecognisable as its component parts!

Step Five

Start using your compost – and spread the word to your family, friends and neighbours!