IRISH GARDENING 



VOLUME IX 

 No, 103 



Edited by C- F. Ball. 



A MONTHLY JOURNAL DEVOTED TO THE 



ADVANCEMENT OF HORTICULTURE AND 



ARBORICULTURE IN IRELAND 



SEPTEMBER 

 1914 



Spring Frost Damage to Forest Trees , 



Bv A. C. Forbes. 



Of the various enemies of the forest, whose name 

 is legion, probably none creates greater havoc 

 or causes greater discouragement than spring 

 frost. Animals, insects, or fungi can separately 

 or collectively damage, or even totally destroy, 

 individual planta- 

 tions or certain 

 species over a wide 

 area ; but damage 

 of this kind is usu- 

 ally localised, and 

 is rarely so wide- 

 spread as to occa- 

 sion serious alarm 

 in this country. 

 Spring frost comes 

 not only when it is 

 least Wanted, but 

 also when it is least 

 expected. On a 

 certain day in May 

 or June, as the case 

 may be, planta- 

 tions and nurseries 

 show the luxuri- 

 ant growth a n d 

 fresh foliage which 

 have inspired gen- 

 erations of poets 

 for centuries back, 

 and the forester 

 feels that some sat- 

 isfactory results 

 are to follow the 

 lal)our of several 

 years' planting and 

 tending. On the 

 following morning, 

 from 25 to 50 per 

 cent, of the pre- 

 vious day's store of vegetation is black or 

 drooping, and thousands of acres of ])lantation 

 appear as if scorched by fire or some ])oisonous 

 exhalation. Had experience and the self- 

 recording thermometer alone give any clue to 

 the cause, for, as a rule, this day does not differ 

 materially from its predecessor, whether as 

 regards temperature or sunshine, and the sensa- 



tions of the average individual seldom experience 

 any change in the weather conditions which 

 would account for such widespread destruction. 

 A glance at the needle of the self-recording 

 thermometer, especially if the instrument rests 



on the grass, ex- 

 plains the matter. 

 The temperature 

 is found to have 

 fallen for a shorter 

 or longer period to 

 an V where between 

 L5° and 25° Fahr- 

 enheit, corres- 

 ponding toa screen 

 temperature o f 

 about 10° or 12° 

 higher. Why it has 

 fallen so suddenly, 

 and why the fall 

 occurs on dates 

 which coincide 

 very closely from 

 year to year, no 

 one knows, lint the 

 end of May and 

 begiiuiing of .hn>e 

 a])])ear to m a r k 

 the period (hiring 

 which the greatest 

 damage is done 

 over an average of 

 years, not only in. 

 this country, but 

 over the greater 

 ])art of Northern 

 Kuro])e, causing 

 incalculal)le dam- 

 age to farm, gar- 

 den, and forest 

 crops and retarding the subse([uent growth of 

 many sensitive species for two or three years. 



Whether Jrelajul suffers more or less than other 

 countries from spring frost cannot be decided 

 offhand, but so far as the year 1!U4; went, there 

 is .some reason to suppose that the damage to 

 young i)lantations exceeded anything recorded 

 within the last twenty or thirty years, taking the 



EW Yl 



rTANI< 



