August 3. 1918 



HORTICULTURE 



107 



Trees Worthy of General Planting in Northeastern States 



Extracts from the ArnnM Arboretiiin Bnlletiu. 



Popuhis Mujimowiczii is a native 

 of eastern Siberia, eastern Saghalin 

 and northern Japan. It is the larg- 

 est tree of eastern Siberia where it 

 sometimes grows eighty feet high 

 with a trunk six feet in diameter and 

 a broad head of massive spreading 

 branches. They have never been at- 

 tacked by borers which make the 

 cultivation of the Balsam Poplars 

 and some of the Cottonwoods so diffi- 

 cult and unsatisfactory, and their 

 leaves apparently have no attraction 

 for leaf-eating caterpillars. Populus 

 Maximowiczil is not only the hand- 

 somest and most satisfactory tree in 

 the Poplar Collection but it is one 

 of the few large exotic trees with 

 deciduous leaves which can be recom- 

 mended for general planting in the 

 northern states. For the list of such 

 trees is a short one. It includes the 

 Gingko, which stands alone in its 

 class and is one of the great trees of 

 the world. Pseudolarix is another 

 Chinese tree which is alone in its class 

 and, although discovered only seventy 

 years ago, it has been long enough in 

 this country to show that it is perfectly 

 able to adapt itself to the Massachu- 

 setts climate. The European Larch, 

 although less picturesque than the 

 Larch of northeastern North America, 

 is a larger and more valuable tree, 

 and the experience with it in New- 

 England shows that it is a tree which 

 can be depended on to grow here 

 rapidly to a large size. 



The two Silver Poplars of Europe 

 (Populus (iJba and P. canescens) 

 flourish in the United States where 

 they have grown to a large size and 

 are as much at home as they are in 

 their native countries. The Silver 

 Poplar of northern China (P. tomen- 

 iosa) is one of the handsomest of all 

 Poplar-trees. It has grown well in 

 the Arboretum but it is too soon to 

 form an opinion of its value in this 

 country. Two European Willows, 

 Salix alha and S. fragilis. and some 

 of their varieties, have become com- 

 pletely naturalized in the north- 

 eastern states where they grow as 

 large or even larger than in Europe 

 and are important additions to the 

 North American silva. The Chinese 

 Weeping Willow (S. hahylonUa) is 

 not always perfectly hardy in Jlassa- 



chusetts, but further south is valued 

 as an ornamental tree. 



Cercidiphyllum is the largest de- 

 ciduous-leaved tree of Japan, and al- 

 though it was introduced into the 

 United States only forty years ago it 

 gives promise of becoming a perman- 

 ent addition to the trees of the larg- 

 est size which can be successfully 

 grown here. The Chinese White Mul- 

 berry (ilorus alba) is a larger and 

 hardier tree than the Mulberry-tree 

 of the eastern states, and is perfectly 

 at home here. Probably the most gen- 

 erally useful, however, of the large 

 deciduous-leaved trees which have 

 been brought into the northern states 

 is the Ailanthus of northern China 

 which must have been growing here 

 for nearly a century. It grows rapidly 

 and is perfectly hardy, and it can re- 

 sist the heat, drought and dryness 

 which trees have to suffer in our 

 cities better than any other tree with 

 the exception, perhaps, of some of the 

 Poplars. 



All foreign Oaks which can be in- 

 duced to live here are proper inhabi- 

 tants of the Arboretum where they 

 are needed for study and public dis- 

 play, but for general planting the 

 Oaks of other countries will never be 

 used in New England in preference to 

 the native species. Of all the Elm- 

 trees of the world not one equals in 

 grace and beauty the White Elm of 

 eastern North America (Vlinus ameri- 

 cana). It is a true lover of the coun- 

 try, however. Moved to the city it 

 soon languishes, for it resents city 

 conditions of overdrained soil, smoke 

 and bad air. One of the so-called Eng- 

 lish Elms is better able to thrive in 

 cities where the American Elm falls, 

 and in Boston and Its suburbs the 

 English tree has been growing for 

 more than a century and has proved 

 itself valuable. None of the exotic - 

 Ash-trees are really valuable here. In 

 the eastern United States no Ash is as 

 good as the American White Ash 

 (Fraj-inus amerirana) for the decora- 

 tion of parks and roadsides and the 

 production of timber. European Birch- 

 trees grew well in the northern states 

 until they were attacked by a borer 

 which destroyed them by thousands. 

 The slender drooping branches of 

 Betula pendula make it an interesting 

 and attractive object but it is not as 



handsome a tree as the native Canoe 

 Birch (Betula papyrifera) which is 

 the handsomest of the white-barked 

 Birches and in one of Its forms ex- 

 ceeds all other Birch-trees in size. 

 Betula Maximoiviczii with pinkish 

 tark, and a native of northern Japan, 

 is, however, a handsomer tree than 

 the Canoe Birch. 



The pale gray bark of the trunk 

 and branches of the American Beech 

 makes It in winter the most beautiful 

 of all Beech-trees, but as a planted 

 tree it does not behave as well or 

 grow as rapidly as the European 

 Beech which, in spite of its darker 

 colored bark, is a better tree for the 

 decoration of our parks. The north- 

 ern Linden (Tilia glabra or ameri- 

 caiia)- is a noble tree in the northern 

 forests, but it does not take kindly to 

 cultivation in a climate as warm as 

 that of Massachusetts. Planted trees 

 grow slowly here; the leaves are us- 

 ually disfigured by red spiders and 

 turn brown and fall during the sum- 

 mer. A planter who wants Linden- 

 trees had best use some of the Euro- 

 pean species. The most satisfactory 

 of them here is Tilia vulgaris, be- 

 lieved to be a natural hybrid between 

 the other western European species 

 T. platyphyllos and T. cordata. No 

 American Horsechestnut or Buckeye 

 can compare in size or in the beauty 

 of its flowers with the species of south- 

 western Europe (Aesculus Hippocas- 

 tnnum). The European Horsechestnut 

 is as much at home here and grows 

 to as large a size as it does in west- 

 ern Europe. It thrives, however, only 

 in deep rich soil and usually resents 

 city conditions. It is a miserable 

 street tree, as can be seen in Paris, 

 where the leaves turn brown and fall 

 by midsummer, and in New. York and 

 Boston where fortunately it has not 

 been generally planted. Among the 

 JMaples of large size which have been 

 planted in the eastern states only the 

 so-called Norway Maple (Acer plata- 

 noides) has shown real power to flour- 

 ish here. It is a smaller and less 

 beautiful tree than the native Sugar 

 Maple, but the Sugar Maple, too, re- 

 sents city conditions and objects to 

 living at the seashore, and as the Nor- 

 way Maple has proved a valuable tree 

 for city and seashore planting it must 

 be considered one of the really valua- 



