April 1902.] The Hardy Catalpa. 113 



It will be seen from the opinions quoted that a radical difference 

 of views upon the subject exists among those competent to speak. 

 The fundamental question is, Shall the plantation be made to develop 

 a forest cover and a forest floor by close planting during the first five 

 to eight years, or shall the trees be planted far enough apart to cor- 

 respond to the arboreal conditions in a fruit orchard, where the open- 

 ness of the tree cover necessitates continuous cultivation to repress 

 the weeds ? 



By planting the rows eight feet apart, with trees standing five feet 

 apart in the row, there would be 1079 trees to the acre. This seems 

 to be about the highest possible limit for the initial planting. It ap- 

 pears reasonable that, with the trees set thus close in the row, the 

 desired straightness of bole could be secured, while the eight feet of 

 distance between the rows would allow considerable space for the de- 

 velopment of an adequate root system, and would afford room for sub- 

 sidiary crops during the first year or so. On the tenth year, by 

 removing every other tree in the row, some 500 posts would be se- 

 cured, and the plantation left with the trees standing 8x10 feet, with 

 544 trees to the acre. According to Mr. Yaggy's judgment, railroad 

 ties could be grown profitably with the trees standing 10x10 feet 

 apart, or 435 per acre, at the* end of eight years. Mr. Brown thinks 

 that the permanent plantation, at the end of eight years, should 

 stand 16x16 feet, or 170 trees per acre. Perhaps this is the most de- 

 sirable distance. The present tendency seems to be to plant at the 

 rate of about 1000 trees per acre, reducing by thinning to about 500, 

 in from the eighth to the twelfth year from planting. It is unfortu- 

 nate that experience with different systems of planting, covering long 

 periods of time, is not sufficiently extensive to enable a conclusive 

 opinion to be rendered at present concerning the proper number of 

 trees for the initial planting. It is safe to say, however, that more 

 than 1000 trees per acre is not advisable. For upland planting fewer 

 trees per acre should be set out than on bottom land with a water- 

 table near the surface. 



The rate of increase in diameter of catalpa trees varies altogether 

 according to the soil, water-supply, and the distance at which trees 

 stand in the forest. In the plantation of the University of Illinois, 

 with trees eleven years old in the forest, and standing four by eight 

 feet, the average increase in diameter in the interior of the plantation 

 is five or six inches, an average of about one-half inch per year. This 

 is the average rate of growth in the Yaggy plantation. There is no 

 doubt that individual trees under favorable conditions, and with ample 

 room, will increase in diameter an inch a year up to an age not deter- 

 mined. That this rate of increase can be maintained under forest con- 



