PROPAGATION OF TREES AND SHRUBS 3 



stated, are those which had rooted when all unrooted cuttings had died. 

 Some investigators, in reporting upon their work, have not made that 

 point clear and one can conclude no more than that a certain treatment 

 or method of handling did or did not hasten rooting; a difference im- 

 portant with some species, not with others. 



Most of the cuttings used here were taken in Amherst, either on the 

 campus of Massachusetts State College or in the garden of the writer. 

 Some of them came from the Arnold Arboretum in Boston and the kind- 

 ness of Dr. E. D. Merrill, in permitting their collection there, is gratefully 

 acknowledged. Amherst is about 90 miles west and inland from Boston 

 but, being in the Connecticut Valley, it is probably less than that distance 

 from the effect of sea on climate, and cuttings of a given species collected 

 at or about the same time in these two towns did not respond very dif- 

 ferently. 



Time of Taking Cuttings 



Time of taking cuttings or age of wood, which is almost but not quite 

 the same thing, is an important factor. Softwood cuttings of some species 

 root well if taken in late summer or after growth has stopped. Cuttings 

 of others root better if taken in late spring or early summer while the 

 wood is still growing. Cuttings of many species can be taken with fair 

 success during a period of several weeks or months. For others, the time 

 limits are narrower, the best time varying somewhat with locality, weather 

 of the season, or from year to year. Cuttings of mayflower root better 

 if the summer has not been very dry (6). Lilac cuttings taken in mid- 

 May one year were equivalent to those taken two weeks earlier the year 

 previously (49). Climatic differences between years may affect response 

 to treatments (18). Cherry cuttings taken at about the end of June 

 responded to a certain treatment one year, not the next (12). The amount 

 of light preceding the taking of cuttings influences their response and it i& 

 possible that cuttings taken during a long period of sunny weather are 

 benefited by a lower concentration of a root-inducing substance (17). 

 Starch content fluctuates but that did not, in the case of hardwood cut- 

 tings of rose, have much effect on rooting (10). 



Occasional reference is made to seasons at which cuttings are taken in 

 England but it does not follow that they are to be taken here at exactly 

 the same times. There is, however, no great difference in the case of 

 certain species. It is English practice to take cuttings of lilac in June, and 

 of Deutzia, Lonicera, Philadelphus, Itea and Viburnum in July; and 

 these are good months in which to take softwood cuttings of those shrubs 

 here. 



Many deciduous species can be propagated by hardwood cuttings taken 

 during dormancy in late fall, winter, or early spring. These are eith«^r 

 planted at once in a greenhouse or, more commonly, stored in moist 

 sand or peat in a cool place until spring when they are set in the field. 

 For such plants as can be thus propagated, this is the simplest method. 

 Among the woody plants which can be propagated in this way are buck- 

 thorns, firethorns, currants, sumacs, alders, grapes, wistarias, buttonbush, 

 trumpet-vine, ninebark, Virginia creeper, bladdernut, tamarisk, Chae- 

 nomeles, Elaeagnus, Akebia, Catalpa, Euonymus (32) and a number of 

 others, some of which are mentioned below. 



