6 



gum. The trees of each species should be planted in separate rows 

 rather than alternated in a single line. The cypress row will then 

 form a dense understory, closing up the lower openings left by the 

 shed branches of the faster growing eucalypts. 



Objection is often made to the blue gum for protective planting on 

 account of its wide rooting habit. It is true that a windbreak draws 

 much moisture from the soil, so that the adjoining rows of orchard 

 trees are often rendered less productive. Wide extension of the roots 

 may, however, be readily limited without injury to the windbreak. 

 At a distance of from 6 to 10 feet from the windbreak a trench parallel 

 to the trees should be dug to a depth of 3 or 4 feet, cutting off the 

 surface roots of the gum trees. Such trenches should then be refilled, 

 but should be reopened every second year. 



METHODS OF PROPAGATION. 



Eucalypts reproduce readily by both seeds and sprouts. The trees 

 bear seed in abundance annually and under favorable conditions 

 natural reproduction is freely established. Trees also sprout vigor- 

 ously from both the stump and the roots, either after cutting or in 

 response to injury. In California commercial groves are almost inva- 

 riably reproduced by sprouts. 



Plantations should be started with young trees and not by direct 

 sowing. The opinion is generally held that eucalyptus seedlings are 

 so difficult to raise that their propagation is impracticable except for 

 expert nurserymen. In point of fact, blue gum is one of the most 

 easily propagated species. With proper attention to details seedlings 

 can readily be raised. 



Seed can easily be collected for planting. The fruit ripens in late 

 summer or fall, but it persists upon the branches and does not open to 

 release the seed until the seed cases fall to the ground. Blue gum 

 seed may frequently be gathered locally from felled trees. Since, 

 however, the seed of the year is not yet ripe at the proper time for 

 planting, it should be collected in the fall and stored until the next 

 season. If kept dry and cool it ^vill often retain its vitality for from 

 four to five years. After the fruit has been collected it should be 

 spread upon sheets in the sun. The seed cases will open and release 

 the seed in a few days. The seed should then be screened or win- 

 nowed in order to separate it from the hulls and chaff. 



When only small quantities are required seedlings may be raised 

 in small beds in a garden. They succeed better out of doors than 

 when raised under glass. They require shade, however, and beds 

 should be protected by lath screens to prevent full exposure to the 

 sun. When seedlings are to be propagated on a large scale, a nur- 



[Cir. 59] 



