Soilless MediaPlant and Soil Science

Standard 4 Objective 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?

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

Advantages of Soilless Mixes

sterile

lightweight

good moisture retention and drainage

free of weed seeds

Disadvantages of Soilless Mixes

minor elements are missing

light weight - pots tip in strong wind

transplants may not adjust well to new media

Content of mixes Soilless mixes contain various

combinations of the following materials.

Perliteimproves aeration

of volcanic origin

Spahgnum Moss Dehydrated remains of acid bog plants

Used to cover seeds because it is lightweight, controls disease, and holds moisture.

Peat Moss Partially decomposed underwater vegetation.

Holds moisture well

Low in nutrients

VermiculiteExploded Mica

Improves aeration

Holds moisture very well

Limestone Raises pH

Hydroponics Technique of growing plants in non-soil

medium using feeding mixture of essential plant nutrients dissolved in H2O

Three main types static solution culture

medium culture

aeroponics