Containers and Substrates

Plant propagation exam 1

What are flat containers used for?

Germinating seeds or rooting cuttings

What materials can flat containers be made out of?

Plastic

Styrofoam

Wood (cedar)

What type of pot system is used for direct sticking liner plants into substrate?

Paper pot system

What is used to germinate conifer seedlings?

Expandable peat pellets

What are community flats used for?

Rooting cuttings prior to transferring to larger containers

What are cons of using clay pots?

Heavy

Breakable

Lose water

Not an economical shape

Salt accumulates

What are pros to using plastic pots?

Reusable

Lightweight

Stackable

Sturdy but flexible

Variety of colors

Reduce irrigation needs

What are cons of plastic pots?

Brittle in the cold

Can be difficult to dispose of/recycle

What kind of containers are used to prevent root circling?

Tiered or ridged containers to interrupt circling

Containers with slits in the side wall to allow air pruning

What type of container is becoming more popular for reducing root circling and because it’s easy to store?

Poly container bags

What is the pot-in-pot system?

Alternative to traditional field production

Tree grown in a pot that is inside a more permanent pot in the ground

What are pros to the pot-in-pot system?

Good soil insulation

Easy to move plants around

Keeps plants upright easier than if they were sitting on top of the ground

What are fiber pots usually made out of?

Peat/wood fiber

What are pros to fiber pots?

Biodegradable

What are “Jiffy” pots and “Ellepots” used for?

Seedlings and rooting cuttings

What are expanded foam (“oasis”) pots used for?

Rooting cuttings

Hydroponics

What is rockwool used for?

Rooting cuttings

Hydroponics

When was the first “substrate” discovered?

1930’s by John Innes Horticultural Institute

Created a loam-based “compost” amended with peat moss, sand, and fertilizer

When was the first true artificial growing substrate created?

1950’s by University of California

Mix of fine sand, peat moss, and fertilizer

What type of mix was the predecessor of modern growing substrates?

Peat-lite

Mix of peat moss, vermiculite, and perlite

What are the 4 functions of growing substrates?

Support (root system)

Aeration

Water holding

Nutrient holding

What is the base of greenhouse crop substrate?

Peat

What is the base of nursery crop substrate?

Bark

What are 5 desired physical characteristics of a substrate?

Uniformity

Easy to wet

Consistent volume

Provides plant support

Weed and pathogen free

What are organic components of substrate?

Peat

Coir

Bark

Sphagnum moss

What are inorganic substrate components?

Sand

Perlite

Vermiculite

Calcine clay

What is the main component in substrates?

Sphagnum peat moss

What are pros of sphagnum moss?

Pathogen-free

Light-weight

High water retention

Fungistatic properties

What are pros of using perlite?

Lightweight

Increases aeration

What are the pros of using vermiculite?

Good pH buffer

Lightweight

High water retention

High CEC

What are pros of coco coir?

Can be formed into different shapes

Sterile

What are rice hulls used for?

Replaces perlite

Increases aeration

What is pumice used for?

Perlite replacement

Provides aeration and drainage

What type of bark is commonly used in the southeast?

Pine

What type of bark is commonly used in the northwest?

Fir

Why is soil seldom used as a substrate?

Variable in its composition

Heavy

What are cons of using sand?

No nutrients

No CEC

No pH buffering

Can fall to the bottom of the substrate

Heavy

Who normally uses sawdust in their substrate?

Forest nurseries

Where are wood shavings commonly used?

South Alabama

Why are wood shavings used?

To reduce peat in the mix

What are substitutes for peat and bark?

Forest biomass

Chipped pine logs

Whole tree

What is the recommendation when using recycled substrate?

Use in small quantities with coarser bark

Don’t use with root rot susceptible plants

What is the target range for total porosity?

50-85%

What is the target range for air space?

10-30%

What is the target range for water holding capacity?

45-65%

What is the target range for bulk density?

0.19-0.52 g/cm³

How do you amend water quality?

Large or small reverse osmosis

What is a soil treatment that isn’t used as much anymore because of health/environmental risks?

Chemical fumigation

How is soil pasteurized?

Using aerated steam

Placing a tarp over the substrate to trap steam with temperatures high enough to kill weed seed, insects, and various pathogens