1. Objective 23.01 Describe horticultural soils.
Learn the advantages & disadvantages of each.

2. 1. Organic matter – dead plant or animal tissue
A. Soils & growing media
1. Organic matter – dead plant or animal tissue
Contains carbon
Usually has diseases or insects, etc.

3. Examples of Organic matter:
Compost
Bark – particles too large to use in seed germination media
Mulch – used to cover soil to help hold moisture, prevent weeds, etc.

4. Straw
Peat moss
Sphagnum
Sawdust – high carbon to nitrogen ratio makes nitrogen unavailable for plant use

5. Wood shavings – high carbon to nitrogen ration makes nitrogen unavailable for plant use

6. 2. Inorganic compounds – do not contain carbon (usually sterile)
Soilless media – artificial soil (no “dirt”)
Vermiculite – mica mineral matter used to start seeds & cuttings, helps hold moisture, has neutral pH

7. Perlite – natural volcanic material that helps aeration & water-holding capacity

8. 3. pH – measurement of acidity or alkalinity from 0 to 14
Acid – less than 7.0 on pH scale
Alkaline – more than 7.0 on pH scale
Most organic matter is acid
Most artificial media is neutral