Fertility in the Japanese Garden

by Jacob Deaver

Photo by Don Olson

Background

• Designed 1985o Landscape architect

Koichi Kawana

• 24 varieties of shrubs

• 20 varieties of trees

• 3 ground covers

• Waterfall, Japanese Lanterns, Garden House, etc.

http://www.arboretum.umn.edu/UserFiles/Image/Japanese1.jpg

Problem & Possible Causes

• Austrian pines o Chlorotico Iron deficiencyo Relatively high soil pHo Lab tests show soil pH of

6.4-6.9 Results likely skewed by

mulch Ideal pH 4.0-7.0

according to Bartletto Soil compactiono Samples sent to UMN for

testing

http://4.bp.blogspot.com/-B1_re_jv9sw/TqXLErBCfoI/AAAAAAAAQmA/pbmfvwb7IBE/s320/pine.jpg

Research

• Foliar feeding?o Short-term, “quick fix” solutiono Potential negative impact on water qualityo “Sprint” used by Dan Miller on Korean pines

• Chelated Iron supplement?o Suggested by Carl Rosen at UMN

Professor & Department Head - Soil, Water, & Climate

Not permanent but provides big nutrient boost

• Lower soil pH?o Amend soil with sulfur or iron sulfateo Makes iron more accessible to plantso Long-term solution

Recommendations

• Short term:o -Use chelated iron in soil around pines to give

nutrient boost Gempler’s Chelated Iron Supplement

o Avoid foliar sprays Generally considered ineffective for nutrient

deficiencies Potential negative impact on koi pond from drift

• Long term:o -Amend soil with sulfur or iron sulfate

lower pH and make iron in soil more accessible to plants

o Address soil compaction

Resources

• Expertiseo Jewel Engstrom & Mary

Bigelowo Dan Millero Carl Roseno Sadafumi Uchiyamao Mary Meyer

• Other resourceso http://www.bartlett.com/

resources/Plant-Health-Care-Recommendations-for-Austrian-Pine.pdf

http://gcrec.ifas.ufl.edu/vtgcrec/pages/BOK%20TOWER%20SANCTUARY/BOK%20TOWER-BC-3-19-03/Bok-BC-Japanese%20lantern.JPG