260 JOUENAL OF THE ROYAL HORTICULTURAL SOCIETY. 



sand, in order to make a bed for the crown to rest on. Plants in open 

 prepared beds do not require lifting so often, and may be left alone for 

 several years, with the exception of an occasional top-dressing of fresh 

 loam and leaf-soil. Altogether there are about twenty species belonging 

 to this genus found in Central and Western Asia, of which about ten 

 have been introduced into cultivation. Of these all but four or five are 

 confined to collections or botanic gardens. — E. T. C. 



Evaporation of Water from Apple Trees during* the Winter. 



By E. P. Sandsten (U.S.A. Exp. Stn. Wisconsin, Ann. Bep. 1904, 

 pp. 258-260). — Four eight-year- old apple trees were sawn off close to the 

 earth and stood among the other trees of the orchard in an upright 

 position. They w^ere weighed weekly, and at the end of the winter 

 (April 3) were found to have lost about 5 lb. per tree (i.e. from 

 15 to 20 per cent, of their total weight at the beginning of the winter). 

 In the succeeding winter, which was moist and with a considerable 

 number of cloudy days, only about 2 per cent, of the weight was lost. 

 It is concluded that, with the exception of the peach and European and 

 Japanese plums, which will not withstand a temperature reaching 

 35° to 40° below zero, winter killing is less due to low temperatures than 

 to drying out of shoots, and so on. — F. J. G. 



Flowering- of Fruit Trees and Meteorological Data. By 



H. L. Price (U.S.A. Exp. Stn. Virginia, Bull. 155; May 1905).— The 

 climate of Virginia is described, and charts showing temperature and 

 rainfall for a period of twelve years are given. The mean annual 

 temperature is 51°-5 ; mean maximum 63°-22 and mean minimum 40°'04 ; 

 the absolute maximum 96° (above 95° on five occasions), absolute 

 minimum —13° (below zero on thirty-four occasions). Average date of 

 last killing frost April 25 (latest date May 13) ; average date of first 

 killing frost September 30 (earliest date September 22). Average 

 rainfall 39*41 inches. Many fruits are self-sterile, and in planting large 

 numbers of trees it is important to intermix varieties that will cross 

 together. It has been found that the European set fruit but rarely when 

 pollinated by Japanese or other types of plum. It is important that the 

 different varieties planted to ensure crass-pollination should flower at the 

 same time. Tables are given showing the dates of flowering of a large 

 number of various kinds of fruit trees during the past twelve years. The 

 dates of flowering of different varieties of plums vary greatly, some 

 flowering as early as April 8, others not till the 26th of the same month. 

 Cherries varied between April 15 and 21, pears between April 16 and 30, 

 apples between April 23 and May 5. — F. J. C. 



Flowering" of Trees, Conditions which Affect Time of. By 



E. P. Sandsten (U.S.A. Exp. Stn. Wisconsin, Bull. 137; April 1906).— 

 After remarking how little is known of the conditions determining the date 

 of flowering of fruit trees, the author shows, by means of comparative 

 tables of temperatures and dates of flowering, that the climatic conditions 

 obtaining during the months of July, August, and on to the end of the 

 year preceding the flowering have a marked influence on the date at 



