Tree Nutrition & Fertilization

Chapter 5

Lorri B Grueber

• City of Lake Saint Louis• Let’s Grow• Norwood Hills Country Club

A word from our sponsors…

Questions before we get started…

Test Day - Thursday April 10, 2008

• Relax!• Remember to think• Chapters/Domains are not

separated• Trust your instincts

Let’s get started…

• Trees have needs, i.e. essential elements

• Urban landscapes may not provide

• Only a soil or foliar analysis can tell

Fertilizer is NOT necessarily the answer!

• Poor prior planning• Lack of education• Play detective before prescribing

I need fertilizer- now what?

• Complete fertilizer• Fertilizer analysis• Organic vs. Inorganic• Slow-release vs.

controlled- release• Water-insoluble

(WIN)

Organic or Inorganic-

What’s the difference?

• Inorganic dissolves quickly in H2O• Available nutrients are released as

inorganic ions (what plants need)• Contributes more to leaching and run-

off• Organic fertilizers also release inorganic

ions (what plants need)• Break down from temperature

Slow-release vs Controlled release

• Contain essential elements in a form that delays initial availability OR extends availability over time.

• Less leaching• Less probability of fertilizer burn

What’s the difference?

• Slow-release:• Less predictable

rate• Depends mainly

on the activity of organisms in the soil (i.e. temp)

• Controlled-release:

• Release nutrients at a specific rate over specific time period

Water-insoluble Nitrogen (WIN)• Defines slow-

release fertilizer• If at least 50%

WIN, slow-release.

Fix these trees

• Park setting• Subdivision built

~4 years ago• Soccer fields built

~3 years ago

Essential elements

• There are 18• See Hopkins café,

managed by my cousin Mocl (C H O P K N S Ca Fe Mg B Mn Cu Zn Mo Cl).”

• Plus Co & Ni

Macronutrients

• N• P• K• S• Ca• Mg

Questions