1. Soilless Media Plant and Soil Science Standard 4 Objective 2

2. Soilless Media  When raising plants there are many different options for a growing media  Most of the time think all plants grow in soil  This is not the case  Does anyone know the kind of growing media we commonly use in our greenhouse?  Is is soil? or a Soilless media?

3. Composition of Potting Mixes  Soil (loamy, good structure, pesticide-free)  Coarse aggregates for drainage (sand, perlite, vermiculite, shredded plastics)  Organic amendments to hold water (sphagnum peat moss, tree bark, sawdust, rice hulls, shredded coconut hulls, wood chip/sludge compost)  Most contain no soil

4. Advantages of Soilless Mixes  sterile  lightweight  good moisture retention and drainage  free of weed seeds

5. Disadvantages of Soilless Mixes  minor elements are missing  light weight - pots tip in strong wind  transplants may not adjust well to new media

6. Content of mixes  Soilless mixes contain various combinations of the following materials.

7. Perlite  improves aeration  of volcanic origin

8. Spahgnum Moss  Dehydrated remains of acid bog plants  Used to cover seeds because it is lightweight, controls disease, and holds moisture.

9. Peat Moss  Partially decomposed underwater vegetation.  Holds moisture well  Low in nutrients

10. Vermiculite  Exploded Mica  Improves aeration  Holds moisture very well

11. Limestone  Raises pH

12. Hydroponics  Technique of growing plants in non-soil medium using feeding mixture of essential plant nutrients dissolved in H 2 O  Three main types  static solution culture  medium culture  aeroponics