ARBORICULTURE 



221 



The Yucca for Planting on Sand Dunes. 



The intimate relation of apparently in- 

 significant objects with those of great 

 magnitude is often passed unobserved 

 The Yucca is neither a forest tree nor 

 even a shrub, simply an herb. Yet we 

 may find great forests successfully 

 grown under the kindly shelter and pro- 

 tection afforded by this humble plant. 



There are two prominent forms of the 

 Yucca, although others are well known. 

 The Adams thread and needle of the gar- 

 dens throughout the Eastern portion of 

 America. Yucca fillimentosa, and the 

 western variety. Yucca glauca, which we 

 illustrate, a dweller of the arid deserts 

 and lower mountains of the mid- conti- 

 nent. 



Both sorts have very large, fleshy 

 roots, which penetrate the soil to con- 

 siderable depth for the purpose of col- 

 lecting and storing water for a long 

 period of drouth. 



On the mesas of Colorado, in gravelly 

 locations, the Yucca is almost the only 

 herb which can survive the prolonged 

 drouths of this region. 



On account of the strong, deep roots, 

 and stored energy of this plant, it is 

 enabled to push upward through a 

 heavy covering of sand, and for this 

 reason the Yucca would be a desirable 

 plant to use upon the vast sand dunes 

 of sea and lake coast to fix the sands 

 which are constantly moved by heavy 

 winds in improtected localities. 



The list of trees and ])lants which will 

 grow under the prevailing conditions 

 of ocean and lake shores, where constant 

 winds build these mountains of sand and 

 roll them along inland, is a very short 

 one, since the sand buries seeds and small 

 plants too deep for them to push through. 



The first object to be accomplished is 

 the elevation of the wind current a few 

 inches above the surface so that it cannot 

 ])ick up the grains of sand. Beach 

 grasses of several varieties are commonly 

 used for this purpose. But these will, 

 in time, be covered up luiless larger 

 shrubs and trees can be started into 

 growth and supported for at least one 

 season, and these grown (|uite thickly. 

 sav 8 b\- 8 feet. 



It is probable that the western Yucca 

 will accomj^lish this object, perhaps in 

 combination with the beach grass, better 

 than by the grass alone. 



Unlimited quantities of the seeds may 

 be secured on the western mesas. This 

 should be grown in nurseries a year and 

 transplanted in the sands either 4 by 4 

 feet or 8 by 8 feet, with grass interme- 

 diate. 



At the same time one or two year trees 

 should be planted among the herbaceous 

 plants at the rate of 500 to 700 per acre. 



Willows, common peach (seed), cat- 

 alpa, wild cherry and rapid growing 

 trees may be interspersed with oak, var- 

 ious pines, etc.. for permancy. 



The Yucca is abundant in western 

 Kansas and Nebraska, and if advantage 

 was taken of its presence to plant hardy 

 trees and shrubs, either the small plants 

 or in some cases the seed, it would be 

 possible at small cost to afforest much 

 of this plains region— but common sense 

 must be used in the selection of ])lants 

 suited to such conditions. 



Of course, plants which thrive in 

 marshes only cannot be made to grow 

 with vigor on dry plains ; cottonwood 

 and elm are among this class, but the 

 bull pine will grow if once planted and 

 protected. It would be a wise act if the 

 U. S. government would turn the Botan- 

 ical Garden, which is merely a politicians' 

 garden, where thousands of dollars are 

 wasted in furnishing congressmen with 

 greenhouse plants and trees not of gen- 

 eral value, into a propagating establish- 

 ment for the growing of economic trees 

 with which to clothe this western plains 

 and Eastern ^Mountain lands. 



Young trees which strike root quickly, 

 and grow rapidly, should be set among 

 the Yuccas at such distance as will en- 

 sure a permanent forest growth. After 

 a few years, Oak and other more valua- 

 ble trees may be established by seeding. 

 Various Pines are used in such loca- 

 tions, but as soil is made with the gradual 

 admixture of leaves, decaying roots and 

 twigs with the sand, \Miite Pine and nu- 

 merous trees of value will be secured by 

 supplying the seed 



