IRISH GARDENING 



53 



Cyaniding 



By James Mathews, Killyinoon, Donnybmok. 



The use ot sodium cyanide as a means of destroy- 

 ing insect pests in plant and fruit Ixouses is not, 

 I believe, practised to the extent it might be, 

 l)artly owing to the belief of the dangers to the 

 ojierator and doubt 5 as to its effects on ])lant life. 



A few notes of my trials and results may be 

 of interest and a helj) to niany of your readers. 

 I have used it extensively for the ])ast three 

 years, and the results have proved so satisfactory 

 that now I use no other fumigant. Being a deadly 

 l)oison care must be exercised in its use. and to store 

 it beyond reach of anyone unaware of itsdangers. 

 1 use p]dwai'd's patent cyaniding ntachine, which 

 is specially constructed to ensure safety to the 

 operator, and by following out the instmctions 

 given with it there is no danger either to person 

 or ])lant. 



It is necessary to have the atmos]jhere of the 

 house dry, and that no moisture adheres to the 

 l)lants, also the temjjerature of the house should 

 be well under 60° F. I have had the best re- 

 sults with the teniperature between .50° and 

 55° ; light must also be subdued to avoid 

 scorching the flowers and foliage. It is therefore 

 best to o]ierate at night. I have used it on 

 various collections of plants in flower, and in 

 various stages of growth, and in no case was any 

 damage done to flowers or foliage* with one 

 exception — a batch of Cinerarias was burned. 

 These plants were fumigated in the evening, and 

 I attril)ute the burning of the foliage to too much 

 light and neglect to ventilate the frame quickly 

 enough, although later these plants broke into 

 fresh gi'owth from the l>ase and made splendid 

 specimens. After this experience I have had no 

 more failures, always operating at night. 



After various trials in strength the quantities 

 I now use tor a greenhouse of about 9,000 cubic 

 teet cai)acity are — sodium cyanide, li ounces : 

 suljdiiu'ic acid (pure), 3 ounces (fluid) ; water, 

 () ounces : which means slightly over the eighth 

 of an ounce f<ir 1,000 fret space, arul tlie cost of 

 fumigating the house about Sd. This strength 

 entirely kills green, wnite and black fly without 

 tliL^ slightest injury to flowers or foliage. I find 

 fumigating abt)ut once a fortnight or so is sufficient 

 to keep the ])lants free of i)ests. Adiantum ferns. 

 even in the earliest stage of growth, show no signs 

 of injiu-y, but they must be dry. 



For the destruction of mealy bug and red spider 

 the quantities must be very much increased. I 

 Used it in a vinery of about 15.000 cubic feet. 

 wher(! i)eaches and (igs were ]ilanted on the back 

 wall — ])eaches were within ten days of ri]>ening. 

 ligs luilf rijte and grajjes lialf coloui-ed. The bugs 

 were getting into the bunches causing much labour 

 to keep in check. With two machines I used 

 sodium cyanide, 3 ounces ; sul])h U'ic acid, 6 

 ounces ; water, 12 oiuices, in each nuiclxine. I 

 reduced tlie temperature to 5K°and kei)t the house 

 closed for IJ hours. Tlu; small bugs were killed, 

 but those in a more advanced stage merely 

 stujjilied, which recovered wlien fresh air was 

 admitted. There was no trace of injury eitlier to 

 fruit or foliage. When I had all fruit cleared off 

 I made another trial, using double the above 

 quantities in each machine, the temperature also 

 at 5S°, and the house kei)t closed over night, 

 (•IxMiing very early next morning. All exposed 

 bugs were killed, also woodlice, wasps and blue- 



bottle flies th.it had been shut in the house- 

 There was no damage done to foliage. 



The ojjeration should be repeated two or three 

 times, at intervals of ten days or so, to kill any 

 insects that may hatch out. Half the above 

 .strength woidd be foimd to kill them at this stage. 

 I have observed, too, that peach trees whicli were 

 infected with brown scale were completely cleared 

 of that pest. For the guidance of anyone^ who 

 may wish to try it, my own methods of working 

 may be of some assistance. 



First obtain the capacity of the house to be 

 operated on, measure out the re((uir<>d quantity 

 of water into the bowl su])]ilied witli each machine, 

 then add the suljdiuric acid in ]iro])ortion and 

 allow the mixture to cool, (("an- must be taken 

 never tcj ])our water on sulphuiic acid.) Next, 

 single out the sodium cyanide ready for use. Fix 

 one end of cord to lever of machine and stretch 

 the other end outside. Alter closing u]) the house 

 put the cyanide in the ])an. then place the bowl in 

 position, and from outside pull the cord to liberate 

 the cyanide. Make sure all doors are secure 

 against anyone entering the house. The gas 

 distributes itself evenly over tbe liouse, so the 

 effects are the same at top and bottom. In 

 about one and a half hours fresh air may be 

 admitted by opening the doors, and in a short 

 time one can enter to open the ventilators. 



The operation is c^uite simi)le, and I feel 

 convinced that if carefully cai'ried out cyaniding 

 is safe, eft'ectnal and economic. 



Saxifraga Boydii and Faldonside 



Boyd's Saxifrage originated as a chance seedling 

 in Mr. Boyd's garden. Cherrytrees, Kelso, 

 Roxburghshire, about ISSO. 



The seedling was supi)osed to come fioiu a late 

 flower of S. burseriana which was i)ollinated l)y 

 S. aretioides. 



S. Boydii is very free flowering, with greyish 

 tufts of leaves and bright yellow flowers often 

 almost seated on small rosettes of leaves. It is a 

 very shy seeder, but two varieties have been 

 raised from it — viz.. Cherrytrees and Faldonsidi'. 



The true Cherrytrees is a mift", now seldom 

 seen and very difllcidt to obtain : a slow grower 

 with greyish tufts of leaves and flowei's, like 

 Boydii. but a very i)ale yellow. 



S. Faldojiside is the (inest yellow-flowei'<'d 

 Saxitrage, with foliage like Bt)ydii. I)u1 with 

 flowers three-(|uart'^'rs of an in.h across, borne on 

 inch high I'eddish stems with glandular haiis. 

 The flowers are a i)aler yellow than S. Hoydii. 

 l)ut the jK'fals are full aiul overlai)ping and 

 slightly aiul ]))ettily crinqx'd, as in some of the 

 Hurseriaua varieties. 



These plants grow well in the moraine or in 

 gritty pockets, and when cultivated in pots or 

 pans a liberal addition of broken biick and inoi'tai- 

 ru])ble should be mixed wit h the potting soil. (See 

 illusiralion. |i. 51 .) 



e^* ^^ c^* 



Primuia Jut-i-e. 



This new sjiecies from the Caucasxis is now in 

 flower and has i)roved hardy and free-growing 

 when given a cool and half-peaty soil in the 

 rockery. It somewhat resembles the common 

 Primrose in habit, but ha- heart -shajied hairless 

 leaves, piu'ple [flowers, ami jjroduces stolon-like 

 growths, by which means it may be<;asily increased. 



