Adding Organic Matter To Your Garden
You should add organic matter to your garden soil, even if you’re not an “organic gardener” for two very important reasons, soil structure and fertility. Regardless of what type soil you find in your garden, increasing the organic content will make it more productive.
It will help break up
heavy clay soils
, making them more workable. Mixing organic particles with those tiny bits of clay keeps the clay from becoming so sticky when wet. It will also keep it from getting rock hard when dry.
It will improve water retention in lighter
. Sand particles are large and drain away water too quickly. Organic particles are all sizes and contain a lot of surface area for water to cling to, leading to more consistent moisture levels.
Every soil type benefits from higher organic content levels. How you add it and how much depends on the type of material and the method of adding it.
What kinds of organic matter are there?
There are three broad categories – green, brown and almost black – relating to the level of decomposition. Here is a look at these materials by type:
Green refers to organic matter that is still alive or nearly so.
(grown to be tilled or spaded under), grass clippings, weeds and other plants just cut down are all examples of green matter.
Green materials will improve soil structure over time and add nitrogen to your soil. But these green resources actually deplete soil nitrogen at first as they break down and compost, before becoming useful to your plants.
Because of this immediate nitrogen need, do not add large amount to your soil just before planting a crop of vegetables. Instead, do one of the following:
- Let the soil rest several weeks after incorporating green.
- Add additional nitrogen
at the time of planting.
- Use the green as
, instead of digging it in.
- Haul the green to the
to be composted first.
(alfalfa, clover and beans) are an exception. Since they fix nitrogen in the soil, another crop can follow almost immediately.
Brown is carbon material after it is dead and beginning to decay or compost. It leaches less nitrogen, but will use some to finish decaying. Like green, brown material is best used as mulch or sent to the compost pile to finish its decay.
Nearly Black is finished
. At this stage, the organic matter has been completely digested and is now a stable source of fast food for your plants. I say fast food because most plants can’t get nitrogen from the air or minerals in the soil, and extracting other nutrients from mineral soils is slow.
Compost, if well made, contains all the nutrients your plants need. This fast food is easily and quickly taken up through their roots. Finished compost, which is called humus, is gardener’s gold, the best plant fertilizer known to man or gnome.
Good gardeners will use green or brown as mulch or as ingredients for the compost pile. Nearly black should be liberally dug into the soil on a regular basis. Native soil typically has an organic content or humus level of about 5%. Your garden will be most productive if you can raise the organic level of your soil to between 10 and 15%.
Your garden plants feed on the humus in your soil. It must be regularly replaced. That means incorporating 2-3 inches of finished compost into the top 8 inches of soil each year.
Learn more about Clay Soil
Learn more about Sandy Soil
Learn more about Silty Soil
Learn more about Loam Soil
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