Organic soil medium info
Hi all i thort this info may be of use to some,I hope to add more info in to the threat as i find it and please feal free to add Eny info you may feel that will help out others.........hempy

TOPSOIL--is a rich mixture of decaying matter and minerals which is the uppermost richest layer of soil. It is sold in nuseries for use outdoors. It looks dark brown .almost black and smells earthy. It is about as organic as you can get. However, it is not sterilized or pasteurized,so it may contain pests or pest eggs as well as fungi and diseases. This is usually not a problem though, Although topsoil works well in the ground,itis a heavy in containers and clumps or packs unless used with otheringredients which lighten it,Packet soil prevents water being distributed unevenly. Part of the medium becomes soaket , while the other parts remains dry.

COMPOST--is an earthy smelling almost black , crumbly mixturecontaining decayed plant matter. It is teeming with life and although not necceearily high in nutrients,it provides a rich environment for the roots . It is acidic unless limed. Some commercial composts are nothing more than chopped up dried plant matter. This material may add some organic matter to the soil, but is not the same as real compost.

WARM CASTINGS--is a compost digested by worms. As they digest the ingredients they concentrate them so that the nutrients are readily available to the plants. It is excellent ingredient in mixes.

HUMUS--is a compost produced in a very moist enviroment. It is very fine textured and rich in nutrients, but quite acidic.

COMMERCIAL POTTING MIXIES--are not soils at all, but mixes containing ingredients such as tree bark, peat moss, wood by-products, as well as artificial ingredients, These mixes have virtually no nutrient value unless fertilizers have been added. Usally mixes with organic ingredients are long on carbon compounds and short on nitrogen, which means they need fertilization. ............In a controlled experiment,researches with the california Dept,of Agriculture found that commercial planting mixes vary in their ability to support plant growth,even with fertilizers added.There was no way of telling which mediums were best without testing them by growing plants in them.

VERMICULITE--is puffed mica which has been *popped* with heat. It is inert, and holds water like a sponge. It is often mixet with other ingredients to loosen the mix and aid in both its water and air retention. It comes in various sizes. The coarse and medium sizes are pefeered because they allow more air to form between the particles than the fine. Vemiculite is very light weight.
( CAUTION dry vermiculite produces a lot of dust which is harmful to breathe. It contains minute amounts of asbestos. Before using the material wet it down with water. This prevents the dust from forming. )

PERLITE--is puffed volcanic pumice. It does not absorb water, but holds it on/in its pitted surface. It is used to lossen plamting mixes andstabilize their water holding properties. It is so light weight it floats in water. It comes in various sizes. Coarse perlite alows the most air to mix with the medium..........(CAUTION Dry perlite produces an obnoxious dust. Wet it down before useing it.)

SAND--both construction or horticultural-was much more popular as a soil ingreddient before vermiculite and perlite were available. It performs manly of the same duties in the planting mix,Stabilizing water retention and loosening the structure. The problem with sand is its weight. Even a cuful of sand adds considerable weight to a container.

GRAVEL--holds a little water on its surface and loosens soil. It is heavy and tends to sink in the medium.

LAVA--holds water on its irregular surface and holes in its structure. It is lighter wight than gravel. It is sometimes used as a hydroponic medium. Glay pellets are sometimes used in place of lava because they are lighter weight.Pea size pieces are the best to use.

STYROFOAM--is hydrophobic, and is used to keep mediums dryer. It is extremely lightweight and tends to float to the surface of the
medium.Usually the little balls are used but sometimes irregular chips are.

PEAT MOSS--is chopped and decayed moss. It performs many tasks in planting mixes. It helps to retain water and holds nutrients and is a nutrient buffer which holds excess nutrients rather than letting them remain too concentrated in the water. For this reson most commercial mixes contain peat moss.It is very acidic and will lower the pH of the medium so that it should compose no more than 20% of the mix.

Here are a few Organic Mixes .....These mixes contain organic ingredients which help to support plant growth and act as a buffer.

1. 4 parts topsoil, 1 part peatmoss, 1 part perlite ,MOIST. Contains medium amounts of nutrients.Best for hand watering systems.

2. 1 part worm castings , 2 parts vermiculite, 1 part perlite. Light weight, high in nutrients.

3. 1 part worm castings, 1 part compost, 1 part topsoil, 2 parts vermiculite, 2 parts perlite, 3 parts styrofoam. Holds high amounts of water and air.

4. 1 part worm castings,1part peat moss, 1 part vermiculite, 1 part perlite,1 part styrofoam. Good buffering capabilites.