PROTECTION OF FEUIT TBEES AGAINST WALLS. 207 



XVIII, — A Note on the Protection of Fruit Trees against 

 Walls. By R. Thompson. 



With reference to the protection of Fruit trees, it may be of 

 utility to state the means employed in the late unusually severe 

 weather, and the results. 



In March the nights were generally frosty ; the wind during 

 twenty-four days came from north-east or east, dry and cold, so 

 that vegetation was fortunately much retarded. In April, the 

 wind still continued to blow from cold quarters, and the dryness 

 of the air increased so that there was not sufficient vapour to 

 form clouds to prevent the escape of heat by radiation ; and the 

 consequence was, that on the nights of the 19th and 20th of 

 April, the thermometer indicated, respectively, 12° and 11° 

 below freezing. According to the register kept at the Garden, 

 this was lower than had been registered for twenty-six years so 

 late in April ; and it appears from Howard's " Climate of Lon- 

 don," that so low a temperature has not occurred so late in the 

 season within the last fifty years. 



Peaches and Nectarines were in full blossom at the time. In 

 the end of March, coping-boards were placed along the wall, and 

 also a net over half of it, and straw screens were placed against the 

 trees on the other half at nights. But previous to the severe nights 

 abovementioned, the net was removed, and straw screens, deemed 

 better protection, were substituted. These screens consisted 

 of one length of the straw fixed on twine stretched between inch- 

 square 6 feet long training-rods. The screen was kept stretched 

 by placing the tops of the rods a a against nails in the wall, 

 whilst the lower pointed ends were in the ground. During the day 

 the screens were rolled up and laid at the bottom of the wall. 

 So far as these extended, the blossoms were sufficiently pro- 

 tected ; but all blossoms on the fronts of the shoots above them 

 were destroyed. Some, however, that were on the sides of the 

 shoots, and leaning close against the face of the bricks, derived 

 as much heat from the latter as kept them alive. On the whole 

 a fair crop has been saved. 



On the Pear walls the blossom was abundant and mostly 

 expanded. Coping-boards were procured for a considerable 

 portion of the walls that were originally furnished with brackets. 

 In addition to the coping-boards a net was suspended in front of 

 the trees on the east aspect ; and elsewhere straw screens were 

 made to project from the top of the wall. Under these the fruit 

 on the upper branches near the straw were saved, but those 

 towards the bottoms of some of the trees were much injured. With 

 few exceptions, however, the crop of pears on walls will be good. 



A glazed Peach frame was covered with mats ; but, notwith- 

 standing this precaution, the blossoms were in great measure cut off. 



