Shade Trees for California 



79 



ultimate height of 40 to 50 feet in Cali- 

 fornia. The unique leaves are medium- 

 sized, fan-shaped, and a clear green in 

 color, changing to yellow in autumn. 

 Because it is hardy and has practically 

 no pests, it is useful both as an orna- 

 mental and shade tree, but it needs 

 extra summer moisture in the drier 

 places. Only male trees should be 

 planted, because the fallen, mature 

 fruits of the female tree have a dis- 

 agreeable odor. 



THE NORWAY MAPLE is a medium- 

 sized, round-headed, spreading, decid- 

 uous tree, 25 to 60 feet high. It has 

 moderately large, light-green leaves 

 that form a dense crown and cast a 

 rather heavy shade. It is relatively fast 

 growing, of average length of life, and 

 hardy. It has proved satisfactory as a 

 lawn and street tree in the interior and 

 mountain valleys of the region, except 

 for a tendency of the roots to raise 

 sidewalks. It is moderately tolerant of 

 alkaline soils. 



The silver maple is fast growing, 

 large, spreading, and 60 to 100 feet in 

 height. Its large leaves, bright green 

 above and silvery below, form a rather 

 open crown, which casts a medium to 

 light shade. The flowers, greenish and 

 in clusters, appear before the leaves. It 

 is hardy, and its useful life is about 

 average. It is similar to the Norway 

 maple in uses and districts to which it 

 is best adapted. Its roots sometimes 

 raise sidewalks. 



THE LONDON PLANETREE is rounded 

 and pyramidal in habit, but becomes 

 spreading with age. It grows to 30 to 

 70 feet, and has large, broad, lobed, 

 green leaves that form a rather open 

 crown and cast a light shade. Its growth 

 rate is rapid; its longevity is about 

 average. Its light-colored bark peels in 

 thin plates. The brown, globular fruit- 

 ing heads, about an inch in diameter, 

 disintegrate when mature. 



It is hardy throughout the region, 

 but it is subject to the sycamore blight, 

 which attacks the leaves, and the syca- 

 more scale. Some strains of the tree 



are practically immune to the blight 

 and resistant to the scale. It is a satis- 

 factory shade and street tree, especially 

 for inland valleys, when propagated 

 from parent stock selected for freedom 

 from blight and pests. The London 

 planetree is alkali-tolerant. 



THE SWEETGUM forms a rounded 

 pyramidal tree, usually reaching not 

 over 50 feet in height in California, 

 with deeply furrowed bark and me- 

 dium-large, deeply lobed, dark-green 

 leaves, paler on the under side. These 

 turn to a crimson or wine purple in the 

 fall. The seeds are borne in spherical 

 heads which are about an inch in 

 diameter and rather prickly on the 

 outside. The tree grows at a moderate 

 rate and it produces a compact head, 

 which casts a medium-dense shade. It 

 is hardy and relatively long-lived, but 

 not tolerant of alkali. The sweetgum 

 is satisfactory as a street tree and for 

 home planting in all parts of the re- 

 gion, except on alkaline soils. It is not 

 adapted to locations exposed to dry 

 winds, and it requires extra summer 

 moisture in the drier localities. 



OF THE VELVET ASH, the Modesto 

 or Montebello forms make a spread- 

 ing but rather compact tree, 30 to 40 

 feet high when mature. The willow- 

 like, deep-green leaves cast a medium- 

 dense shade. Fast in growth, it is hardy 

 except at high elevations in the region. 

 In longevity it is about average. It is 

 drought-resistant, moderately tolerant 

 of alkali, and more resistant to the red 

 spider type of mite than the regular 

 form. It is subject to occasional de- 

 foliation by insects in some districts, 

 but these pests can be controlled read- 

 ily by sprays. A popular shade and 

 street tree for the interior valleys, it 

 stands drying winds well and succeeds 

 with little moisture. Recently a leaf 

 disease has appeared in parts of the 

 region which may make it less desir- 

 able as a shade tree in the future. 



THE CAROLINA POPLAR, a tall, up- 

 right tree from 40 to 100 feet in height, 



