188 JOUENAL OF THE ROYAL HORTICULTURAL SOCIETY. 



applied after scraping off all the rough old bark, will answer the double 

 purpose of killing injurious insects and protecting from scald. The 

 following mixture makes a good tenacious wash for the purpose: — 



Quicklime 30 lb. 



Tallow 45 lb. 



Salt 51b. 



Water enough to make the mixture flow well. Young peach trees 

 are also liable to injury when the temperature falls, as it does in 

 Colorado, lower than 15^ below zero, and it is sometimes hard to tell 

 until early summer how much damage has been done, so that after 

 a severe winter it is as well to delay pruning until about May 1, so as 

 to be sure where to prune. Even then peach trees may be so injured 

 as to succumb gradually, months or even a year or two after a severe 

 frost. 



The proper management of irrigation is an important matter in pre- 

 serving young orchards from the effects of low temperatures. Unripened 

 growth falls an easy prey to the first autumn frosts. There is, on the 

 other hand, another form of winter injury among old and young trees 

 alike known as " freezing dry." This is thought to result from two 

 causes — lack of moisture in the soil, and a, deeply frozen condition 

 which stops all root action. To prevent this irrigation in late autumn 

 or early winter is necessary. Ice round the base of a tree occasionally 

 results in injury in the form of partial or complete girdling at the 

 ground line, which in some instances is hard to distinguish from the 

 injury due to arsenical poisoning. With peach trees there is always 

 the danger of the fruit buds being nipped by spring frosts. To combat 

 this, there seems great faith in Colorado in the advantages of orchard 

 heaters, either oil or coal, preferably the former. — M. L. H. 



Wood, Sapstain in. By I. W. Bailey (Bot. Gaz. pp. 142-47, 

 Aug. 1910). — The author finds that sapstain in wood is due either to 

 the attacks of fungi or chemical discoloration. The latter is caused 

 by oxidizing enzymes. Hot humid weather is favourable, and cold i 

 winter weather is unfavourable to these ferments. These enzymes are I 

 destroyed and their action prevented by a temperature of 100° C. ' 

 Treating sapwood of alder, birch, and cherry with boiling water 

 destroys them and prevents the sapstain. Treating sap lumber in long! 

 tanks of boiling water appears to be a practical method of preventing! 

 this discoloration adapted to saw-mill practice. — G. F. S. E. 



Yucca Whipple! (Gard. Chron. p. 106; Feb. 17. 1912; 2 figs.).— 

 A record of the flowering of Yucca Whipplei at Aldwick Manor, Bog- 

 nor, in the summer of 1910 in the open, after living out with winter 

 protection for 6-8 years. — E. A. B. \ 



Zyg-opetalum Mackayi Charlesworthii {Gard. Chron. p. 83, 

 Feb. 10, 1912 ; with fig.). — An albino form, with no purple markings on 

 P. tomentoswm. The plant is sterile so far. 



