Horticulture Science

Unit A

Horticulture CD

Growing Media, Nutrients, & Fertilizers

Problem Area 4

Understanding Properties of Growing Media

Lesson 1

Vermiculite>>>>>

Interest ApproachWhat makes a great

basketball team?• 5 or more members that work well together.• At least 1 who can score points from 20’ +.• At least 1 who can be used inside the key.• 1 or more who can control the ball.• 1 or more to push the ball inside.• Each player has their strengths!

Interest ApproachWhat makes a great growing

medium?• Several components that work well

together

• 1 or more that hold water.

• 1 or more that hold air.

• 1 or more sources of nutrients.

• 1 or more to help defend against pest.– Components that are sterilized.

Interest ApproachWhich Makes the Best

Growing Medium?• Sand

• Peat Moss

• Field Soil

• Vermiculite

• Pearlite

• Water

• Gravel

Student ObjectivesBy the end of this lesson, you

will be able to:• 1. Identify the types of growing media.

• 2. Describe the functions of growing media.

• 3. Explain the relationship between growing media and plant growth.

TERMS

• Aeration – the presence of air• Growing medium – material used for plant

growth• Hydroponics – growing plants w/o “soil”• Leach – to remove by percolation• Pore spaces – voids for water or air holding • Soil – outer layer of the earth suitable for plants• Soilless medium – sterile product/s used for

plants

What are the types of growing media used in floriculture

production?• Is “soil” used?

• Soil – the earth’s outer crust is full of life!– Bacteria– Fungi– Invertebrates

What are the negatives of using “SOIL” for containers?

• Unknown history of:– Pesticides– pH– Fertility level

• High shrink / swell– Soil shrinks as it dries – forming cracks

• Higher disease probability

So what media should you use?

• Sand? Dries to quickly.

• Peat moss? Dries to slowly.

• Coir? Hard to get wetted.

• Water? To little air.

• Pearlite? To much air.

• Vermiculite? Pricey.

• Potting soil mixes? Just right.

The 3 basic types of media!

• Soil – natural layer of the earth that supports life.

• Soilless – any material for growing plants not containing topsoil.

• Hydroponics – plants grown primarily in nutrient solution.

What are the functions of the growing media?

• Must provide AIR.

• Must provide WATER.

• Must provide Nutrients.

• Must provide ANCHORE / SUPPORT.

What effect does growing media have on plant growth?

• Supplying Nutrients

• Some media cannot hold essential elements for plants. Nutrients are leached out to rapidly.

• Stressed plants are prone to disease and insect damage – increasing loss.

• Reduced growth = lower returns

What effect does growing media have on plant growth?

• Supplying Air

• As air is reduced, plant stress increases.

• Roots need oxygen and water – both in moderation.

• Increasing stress increases pest susceptibility and profit loss

Necrotic line patterns in the foliage of a cyclamen affected by impatiens necrotic spot tospovirus

(INSV).

What effect does growing media have on plant growth?

• Uniformity

• Large scale production demands that all plants perform equally.

• This is only possible if all plants get equal inputs from a uniform media.

Review

What are the 3 types of media?

• Soil – define

• Soilless– define

• Hydroponics– define

What are the functions of growing media?

• Supply Air.– Why?

• Supply water.– Why?

• Supply nutrients.– Why?

• Supply support / anchor.– Why?

Why is it important for media to:

• Supply nutrients?• Increase healthy plants,growth and

returns.• Supply air?• Reduce diseases and increase profit.• Supply uniformity?• Plant schedules require uniform plant

growth!