Shade Trees for the Plains 



in storms. Large, old trees near houses 

 are often dangerous. The cottonwood 

 should not be planted on streets, except 

 where more suitable species will not 

 grow. 



Other species, such as Lombardy 

 poplar and the hybrid Carolina poplar, 

 have also been used widely but are 

 better suited to the eastern edge of the 

 Plains area where rainfall is greatest. 



THE AMERICAN ELM, perhaps the 

 most beautiful broadleaf tree, some- 

 times reaches 90 feet in this region. 

 This elm has a symmetrical, vase- 

 shaped crown that frequently attains a 

 width of 60 feet or more. It lives to an 

 age of 75 to 100 years on the better 

 sites, provides moderately dense shade, 

 and grows moderately fast. Its small, 

 brown flowers appear in early spring 

 before the tree leafs out. It prefers 

 deep, rich, moist loam, but it will stand 

 adverse soil and weather conditions 

 and does fairly well even on sandy 

 exposed sites. 



In the Plains States, American elm 

 is often seriously attacked by the elm 

 leaf beetle and European elm scale. 

 The elm sawfly causes defoliation at 

 times. The wooly elm aphid is also 

 abundantly present, especially during 

 wet seasons. A fungus leaf spot disease 

 is common. Phloem necrosis has been 

 found in eastern Nebraska, Kansas, 

 and Oklahoma and is a serious menace 

 to the existence of the American elm 

 throughout the Plains. We fear that 

 phloem necrosis will progress rapidly 

 westward; until a method of control 

 is discovered for this destructive dis- 

 ease, we advise against planting the 

 American elm. Trunk rot due to a 

 fungus is fairly common in planted 

 street trees. American elm is suscep- 

 tible to cotton root rot and should not 

 be planted on soils infested by this 

 fungus. Rabbits are another enemy. 



THE SIBERIAN ELM, often sold un- 

 der the name of Chinese elm, has been 

 planted perhaps more widely than any 

 of the other introduced species. It 

 grows rapidly to a height of 50 to 60 



feet. The main branches tend to grow 

 upward and form sharp crotches that 

 are easily broken by wind. Slime flux 

 commonly develops in such wounds. 

 The species provides moderately dense 

 shade. Small purplish flowers appear 

 in early spring before the leaves show. 

 It does best on sandy loam soils, but it 

 will also grow on sandy sites of low 

 fertility. It lives about 50 years or less. 

 It is drought-hardy, but, because it de- 

 velops its leaves early in the spring and 

 retains them later than most trees in 

 the fall, it is in constant danger of 

 severe damage by unseasonable freezes. 

 Cytospora fungus cankers cause further 

 damage to frost-injured trees. Siberian 

 elm is highly susceptible to cotton root 

 rot and cannot be used on soil infested 

 by the fungus. Rabbits often damage it 

 severely. This species is used for both 

 street and yard planting, but is now in 

 general disfavor because of its sus- 

 ceptibility to frost damage. 



COMMON HAGKBERRY makes a mod- 

 erate growth up to 50 to 70 feet, and 

 develops a large, rounded crown. Its 

 spreading branches provide moderate 

 shade. The small, greenish flowers ap- 

 pear in late spring. It prefers a rich, 

 moist, and well-drained soil, but it will 

 grow successfully on practically all 

 types. The common hackberry is frost- 

 hardy and withstands heat well. It 

 attains an age of 60 to 70 years. 



Webworms commonly cause defoli- 

 ation, especially of young trees. This 

 species is subject to rabbit damage. 

 Witches' brooms are a distinguishing 

 feature of older trees and are regarded 

 as undesirable, but they do not se- 

 riously affect the health of the trees. 

 Several minor leaf diseases occur on 

 this species. It resists cotton root rot, 

 and is drought-hardy when once es- 

 tablished. It will not stand extensive 

 flooding. 



The common hackberry is a good 

 street tree and should be used more 

 extensively in this region. 



THE BUR OAK,, a large, slow-grow- 

 ing native tree, reaches a height of 80 



