Q. From some things I’ve read it sounds as if you advocate using a soil-less growing medium, like in hydroponics. Is that correct? And if so why?
A. If a person chooses to grow in containers – which we like to do in certain situations, such as where people have no soil, or very little space, or if their soil is toxic or so rocky that it can’t be worked – then we recommend a mix of clean materials such as sawdust, peatmoss, perlite, and sand.
This eliminates problems so often caused by weed seeds, pests, and diseases that are many times found in natural soils. Nutrition is provided by the two natural mineral nutrient mixes included in all the books and on the website.
In the large majority of situations, however, we suggest people grow in their existing soil. We do not recommend soil amendments as an essential, or even important part of the gardening process, simply because most people cause more problems than they solve in adding “compost”, etc. to the soil. The problems come from improper and/or incomplete composting of the materials, resulting in the same problems that exist in the soil itself, i.e. weeds, pests, and diseases being introduced into the garden.
If plant residues are composted properly, the core temperature of the material will be sustained at 140 degrees fahrenheit virtually full-time for about 3 weeks. This kills all weed seeds, soil pests and pathogens, and the compost is safe and healthy for gardens. For an example of this being done, read The ZooDoo Man article in this section of the website, which describes my 2-year experience making and selling “the world’s best compost” at Utah’s Hogle Zoo.
The nutrition we give the plants is the same, whether in the soil or in containers. For this reason the Mittleider Method is sometimes called “the poor man’s hydroponic method”. We feed the same because we have found that most soil is deficient in some or all of the 13 elements plants need from the soil, and for the family gardener it is much more efficient and cost effective to provide proper nutrition than to expend the time and money for soil tests, and then have to find, buy, and mix whatever elements are recommended.
Doing this has never caused excess fertilizer problems for the soil or the plants, and our gardens have been found to be clean, healthy, and free of any toxicity wherever we have been.