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