TKEES IN TOWNS 47 



a natural state, numerous species may be grown, if the 

 smoke nuisance is slight. 



As regards planting in towns generally, the choice of 

 trees should be restricted to really hardy species, which can 

 live and thrive in the climate of the district, and which 

 are capable of withstanding wind, if the situation is at all 

 exposed. Species not liable to attacks of fungi and insects 

 are also very desirable. The difference in the climatic 

 requirements of trees is much greater than is generally 

 supposed. For example, some American trees, like the 

 black walnut and the tulip tree, which make noble specimens 

 in the Thames valley and farther south, are often poor and 

 stunted in the north of England and Scotland. The 

 Chinese Paulownia i'ntperialis, which is magnificent in Paris, 

 is unlikely ever to succeed in any of our towns. New and 

 rare trees, which may be seen flourishing at Kew, Glasnevin, 

 and other botanic gardens, ought to be tried in town parks 

 and spaces blessed with good soil, and not in streets, where 

 all the conditions are unfavourable. 



Different species of trees vary much in the quantity and 

 density of their foliage, and this affects their suitability for 

 planting in streets. Some kinds, as the beech, carry a 

 dense heavy crown of leaves, under whose shade nothing 

 can grow. Trees of this class are not desirable in streets, 

 as they keep the roads and pavements wet for long periods 

 after rain, and prevent sunshine from reaching the houses 

 in narrow streets. Other sorts of trees, of which birch and 

 Eobinia are good examples, bear light and sparse foliage, 

 which casts little shade. Such trees are suitable for street 

 planting. 



The size to which trees will grow in time is a matter of 

 importance, as it is only in great wide streets that trees 

 of the first magnitude can be safely planted. The form of 

 trees must also be considered. In confined sites and narrow 

 streets, trees of a columnar or narrow pyramidal habit are 

 the most suitable. 



A few remarks on the species most suitable for towns 

 will be useful. 



