All the areas on the Exposition site were composed of drifting sands or
sands that had been pumped in from the bay, upon which no ornamental
plant could grow.
It was necessary to bring down from the Sacramento Valley rich soil
(fifty thousand cubic yards), and spread sixteen thousand cubic yards of
fertilizer over that, in order to maintain lawns, trees and shrubs.
An immense number of trees, ranging from thirty to sixty feet in height,
were moved from Golden Gate Park and the Presidio of San Francisco. It
is the largest number of evergreen trees ever moved in connection with
any landscape work.
Many plantings will be made thruout the Exposition. It will require the
moving of four hundred thousand plants each time a change is made.
Work on the eucalyptus trees was started two years ago, when the plants
were six inches high, in flats.
These little trees were transferred into other flats and placed on hot
beds. After six weeks of this treatment they were transferred to 12-inch
boxes. They remained there for a period of eight months and then were
put into 18-inch boxes and made a vigorous growth. They are now 25 feet
in height.
In boxing large specimen trees the following method was adopted: The
trees were side-boxed, and, after the roots were cut, three inches of
space was allowed between the ball and the sides of the box, and this
three-inch space was secured with good surface soil so as to start
side-root action.
The plants were mulched and watered for a period of from four to six
months, when the bottom of the box was put on. This method has been most
successful in transplanting palms and trees in general.
(These facts were kindly given by Mr. Donald McLaren of the Department
of Landscape Gardening, San Francisco.)