72 



THE QARDENERS' MONTHLY 



[March, 



THE CARNATION DISEASE. 



BY CHARLES HENDERSON. 



I may be repeating something already said in 

 the Monthly about this matter, but it is of such 

 importance that I think most of your readers inte- 

 rested will excuse it. I think we have demonstrated 

 that the cause of the Carnation disease, and, in 

 fact, of most of the other diseases of plants is, first, 

 from lessened vigor in the variety, first caused by 

 treatment contrary to what the nature of the plant 

 demands. To begin with, the Carnation for the 

 past twenty-five years has been forced for winter 

 flowering in almost every section of the country, 

 and nearly in all cases by the same process of 

 keeping a temperature at night, averaging, from 

 November to April, at least 55"^, with perhaps 15O 

 more during the day. Cuttings are taken off from 

 the forced plants, put into a propagating house, 

 often at a high temperature, and when rooted are 

 grown along at the same temperature at which the 

 plants that are forced for flowers are grown, until 

 they are planted out in the open ground in May, 

 where the temperature outside is nearly as high as 

 that they have been enduring under glass. Now 

 when we consider that the Carnation is nearly a 

 hardy plant, demanding for its best growth a period 

 of rest in winter, the wonder is that it has not re- 

 belled long ago against such bad treatment ; but 

 the complaints are now so general that it is evident 

 that unless some means are used to avert the trou- 

 ble, it will soon be the exception to find a healthy 

 stock of Carnations in winter. Some kinds seem 

 to succumb sooner than others. La Purite was 

 one of the first to give out, but there is hardly now 

 a variety that has been grown for six years, but 

 in some locality or another is failing. There 

 are two ways in which the trouble may be pre- 

 vented, the first of which we have been practising 

 for a number of years with complete success with 

 every variety except La Purite, and even that has 

 much improved. Our plan is to take the cuttings 

 oft' during November and December. They get 

 rooted enough to fill two-inch pots by about 

 this date (February ist), when they are knocked 

 out of the pots and the balls packed close in shal- 

 low flats, holding one hundred or so, and they are 

 then put either into cold houses or the ordinary 

 cold frames, and covered up with straw mats so as 

 to keep them from being severely frozen. Kept 

 in this way, they can be planted out just as soon 

 as the ground is dry enough in the Spring, usually 

 about April ist. The other plan, which we tried 

 for the first time last winter, is to heel away our 



stock plants in cold frames, and take the cuttings 

 from these any tirhe from January to March. The 

 object in both cases is the same ; to rest the plants, 

 as their nature demands. Mr. John Murchie 

 covers the whole ground, we think, when he says, 

 " Quit striking your plants from plants that have 

 been forced." Now, if it be true that the Carna- 

 tion disease is a consequence of uninterrupted 

 " forcing " from year to year, I think we need not 

 look further to find the reason of many of the other 

 ills that plant life is heir to. The "sickness" 

 among Violets is so general now, that it is rare to 

 find a healthy stock. They, too, like the Carna- 

 tion, have been forced for a generation, and though 

 at not quite' so high a temperature as the Carna- 

 tion, yet certainly at a higher temperature in 

 winter than they would be in their natural habitat. 

 If this is the cause, the remedy is obviously the 

 same as in the Carnation — give the stock from 

 which you propagate a rest in winter. That debi- 

 lity in vegetable life invites parasitical germs can- 

 not be doubted. All experienced propagators 

 know that excessive cutting of a new plant for 

 stock, not only renders the original plant itself 

 liable to parasitical attacks, but the weakness fol- 

 lows into the progeny for years. 



We have several cases in point this season. 

 The new Heliotropes, Swanley Giant and King of 

 Night, are both affected with black rust, while in 

 over twenty other varieties in our stock not a sign 

 of it is present. " Black Rust," so termed, affects 

 many species of plants, but is best known as af- 

 fecting Verbenas and Heliotropes. When ex- 

 amined by a powerful microscope it is found to be 

 caused by a lobster-like insect, which rarely at- 

 tacks plants in health. In fact we have proved 

 again and again that when plants such as Ver- 

 benas and Heliotropes have become pot-bound 

 the insect attacks them, while those shifted at the 

 proper time and stood alongside of them have 

 been completely exempt from its ravages. But to 

 return to Carnations. You, Mr. Editor, are prob- 

 ably correct in saying that we can not combat 

 with the disease when its attacks are made in the 

 forcing benches. If, however, the debilitated 

 state invites fungus there may be a temporary 

 remedy in using lime water, made by using about 

 half a pound of lump lime to each gallon of 

 water and putting it on clear, when the soil is dry 

 enough to require water. The best Rose growers 

 in this vicinity use lime water in the same way 

 whenever there are indications by paleness of the 

 leaves that this insidious parasite may be sapping 

 the roots. .Another parasite of the Carnation that 



