﻿60 BULLETIN 24, U. S. DEPARTMENT OE AGRICULTURE. 



TIME TO PLANT. 



Spring planting is recommended. In the Northern States, in par- 

 ticular, fall or winter planting is likely to meet with poor success. 

 The alternate freezing and thawing of the ground during the winter 

 will often lift the plants entirely out of the ground. This applies 

 equally to cuttings and seedlings. On light, sandy soil, however, 

 this danger is comparatively small. In the south of the valley the 

 danger of frost heaving is slight, and if planting is not done on 

 very heavy soils there are advantages in planting during late 

 fall or winter. Seedlings planted early in the fall will recover 

 from any root injuries and become well established before spring. 

 In fact, stock planted early in the fall will continue root activity 

 well into the winter, and therefore will begin growth early in the 

 spring. This will enable it to withstand better the spring overflow, 

 which in the South is apt to occur within 4 or 5 weeks after vegeta- 

 tion begins. Furthermore, autumn planting is better in localities 

 subject to prolonged drought in the spring. In general, however, 

 fall planting, at least for the present, should be restricted to rooted 

 stock, as it is still uncertain how well plain cuttings would withstand 

 long exposure throughout the winter and overflow in late spring. 



PURE VERSUS MIXED PLANTING. 



Cottonwood may be planted either pure or in mixture with other 

 species. An advantage of pure plantations consists in the greater 

 simplicity of field planting and its consequent lower cost, especially 

 since cottonwood stock is usually cheaper than that of any other hard- 

 wood tree that might be used in mixture with it. Pure plantations 

 yield a larger quantity of solid wood on a short rotation. 



The advantages which may possibly result from mixed planta- 

 tions are a possible increase in the board-foot yield ; an improvement 

 in the quality of the timber, due to clearing cottonwood of its 

 branches; and in shading the ground. Mixed planting is particu- 

 larly of advantage in the establishment of windbreak?, for which 

 cottonwood, as it matures, becomes too open to be thoroughly effective. 



The associate species ordinarily would have no value, except pos- 

 sibly for cordwood. It would act chiefly as a " filler " to improve 

 the quantity or quality of the cottonwood. Any of the following 

 species would make suitable fillers : Silver maple (Acer saccharinum 

 Linn.), boxelder (Acer negundo Linn.), sycamore (Platanus occi- 

 d entails Linn.), white ash (Fraxirms americana Linn.), and green 

 ash (Fraxirms pennsylvanica Marsh). Probably the silver maple 

 will be the most suitable species. One-year-old maple seedlings can 

 be purchased from dealers for $2 to $3 a thousand. If a filler is 



