FERTILIZING AND WATERING TREES 19 



5. Discontinue fertilization when it fails to accomplish a 

 purpose or when other factors become of primary concern. Often 

 fertilizing can be continued indefinitely. Some woody species, 

 however, may become succulent or develop a weeping appearance 

 after prolonged fertilization. All fertilized plants should be care- 

 fully observed each year. 



Watering 



1. Prepare a dike 3-4 inches high around the planting hole 

 of a recently planted tree. During the growing season fill it with 

 water at 7- to 10-day intervals until the root system has become 

 established. 



2. During droughts or extended dry periods in the summer, 

 water established trees with a lawn sprinkler with the equivalent 

 of 2 inches of rainfall at intervals of 2-3 weeks. 



SELECTED REFERENCES 

 Fertilizer-plant relationships 



Bear, Firman E. 1965. Soils in relation to crop growth. Reinhold Pub- 

 lishing Corporation, New York. 297 p. 



Berger, Kermit C. 1965. Introductory soils. The Macmillan Company, 

 New York. 371 p. 



Black, C. A. 1957. Soil-plant relationships. John Wiley & Sons, Inc., 

 New York. 332 p. 



Teuscher, H., and R. Adler. 1960. The soil and its fertility. Reinhold 

 Publishing Corporation, New York. 446 p. 



Organic vs. inorganic fertilizers 



Donahue, Roy L. 1965. Soils: an introduction to soils and plant growth. 



Second edition. Prentice-Hall, Inc., Englewood Cliffs, New Jersey. 



363 p. 

 Millar, C. E., L. M. Turk, and H. D. Foth. 1965. Fundamentals of soil 



science. Fourth edition. John Wiley & Sons, Inc., New York. 491 p. 



Tree fertilization experiments 



Chadwick, L. C. 1935. The fertilization of shade trees in the nursery. 

 American Society for Horticultural Science Proceedings for 1934. 

 32:357-360. 



. 1937. Fertilizer trials with shade trees in the nursery. Ameri- 

 can Society for Horticultural Science Proceedings for 1936. 

 34:664-668. 



Himelick, E. B., Dan Neely, and Webster R. Crowley, Jr. 1965. Experi- 

 mental field studies on shade tree fertilization. Illinois Natural 

 History Survey Biological Notes 53. 12 p. 



Tree planting and care 



Carter, J. Cedric. 1966. Illinois trees: selection, planting, and care. 

 Illinois Natural History Survey Circular 51. 123 p. 



