November 13, 1915 



HOETICULTUEE 



ROSE GROWING UNDER GLASS 



^ ~ CONDUCTED BY 



Questions by our readers In line with any of the topics presented on tbis page will be cordially received and promptly answered 

 by Mr. Ruzicka. Such communications should Invariably be addressed to the office of HORTICULTURE. 



Mildew on Outdoor Roses 



Mr. Arthur Ruzicka, 



Dear Sir: Can you give me some formula to be used 

 for mildew other than sulphur flowers, on outdoor growing 

 roses? I would like to overcome mildew on outdoor roses 

 and up to the present time have not been successful. 



What would you advise? Can you give me informa- 

 tion as to where I could procure new German roses? 



Would like to know of some German rosarians in 

 Germany. 



Thanking you, I am, gratefully, 



M. H. S., Walla Walla, Wash. 



Mildew on outdoor roses is much more difficult to 

 control than in the greenhouses, for outside you have 

 no control of heat or cold, dry or wet, so that it may 

 be almost impossible to keep your roses free from mil- 

 dew. Spraying three times a week with Fungine will 

 do a good deal to prevent the disease, and all mildew 

 will be killed instantly on coming into contact with the 

 spray. Grape Dust is also used, but is objected to at 

 times because the leaves must be dusted with it. Sulphur 

 mixed with a little lime can also be used, but this too 

 will be objectionable because of the dust on leaves. 

 Fungine will not mark the foliage, will cleanse it if any- 

 thing. In spraying white roses in full bloom, be care- 

 ful not to let the spray hit the flowers very much, as 

 it is liable to discolor these. 



I have never been on the Pacific-Northwest coast, so 

 perhaps some rose growers either in your state or in 

 California could help you more than I can. As for 

 names of German firms in Germany, I am sorry to say 

 I know none, and doubt very much that you could get 

 into communication with any firms over there at pres- 

 ent, because of the war. There are some good firms ad- 

 vertising in Horticulture, who make a specialty of 

 rose growing, and who have acres and acres of accli- 

 mated stock, in all the leading varieties, and I would 

 advise you to look over these firms' catalogues or write 

 to them, and I am sure tliat you will get better satisfac- 

 tion than importing from a foreign country. Perhaps 

 some one connected with the (Jemian Embassy or 

 Consulate in this country could furnish you names of 

 these firms, or some of Horticulture's readers may 

 know of German finns who make a specialty of grow- 

 ing roses. 



Blackspot on Roses 



Mr. Arthur Ruzicka. 



Dear Sir: Will you kindly explain to me why you recom- 

 mend amraoniacal copper solution for blackspot on roses, 

 at the same time recommending Fungine? 



I have used the latter for several seasons with excel- 

 lent results. A short time ago I took over a place, which 

 had a large stock of the older insecticides in the potting 



room, and the only fungicide was the copper solution. I 

 invariably spray roses each week with Fungine, but at this 

 place could not order until the other fungicide had been 

 used up. I sprayed a couple of weeks ago with the copper, 

 using the prescribed dose and all the young growths were 

 scalded. It was a dull day and what surprised me was 

 the fact that a batch of Alternanthera Jewel and nana 

 compacta that were on a shelf on one side of the house 

 that did not some in contact with the spraying were liter- 

 ally scalded. Can it be that the ammonia fumes in the 

 compound were too strong or what? I mixed in a wooden 

 pail as I always do Fungine. 



I shall never use the copper solution again but shall 

 stick to Fungine. It is the best fungicide I know and I 

 would not be without it. 



Yours truly, 



W. R. F., New York. 



Speaking from personal experience, we have not had 

 a serious case of spot for a long time, and we have had 

 little occasion to use either copper carbonate or Fungine 

 for the disease mentioned, and as we are interested in 

 roses commercially, we have not been spraying regularly, 

 in order to keep operating expenses as low as possible. 

 I do not remember recommending a prepared solution 

 of the ammoniacal copper carbonate such as you men- 

 tion, having always preferred to use home-made mix- 

 ture whenever we had occasion to use same. From your 

 letter I would be of the opinion that the mixture was 

 old, and possibly badly settled to the bottom of the con- 

 tainer. If this was the case, the amount of ammonia 

 jioured off would be out of proportion with the other ma- 

 terials in the mixture, and the chances are it would be 

 too strong. You mention spraying on a cloudy day: 

 thi.-;, I think is a mistake when using the copper mix- 

 ture for a spray. I would much prefer a clear day, when 

 the houses can be aired freely, so there will be little 

 danger from the fumes. Of course with nicotine solu- 

 tions it is different, and these should be used on cloudy 

 days wlien there is little air on the houses in order that 

 full benefit of the spray may be obtained. Fungine is 

 a very good article, and has been advertised freely, and 

 I think I am right in assuming that all progressive 

 growers should be familiar with it. I would recommend 

 a number of patented articles that are real good to liave 

 around the greenhouses, but there would be growers who 

 would fail to get the desired results even with the most 

 minute directions, and the outcome would be that I 

 would be accused of accepting pay for doing so. That 

 is why I recommend mixtures that are home-made as 

 far as possible, and if the grower does not get the re- 

 sults expected, his failure can usually be traced to his 

 own mistake. This is also true of using prepared arti- 

 cles, but they can always be blamed for not being mixed 

 right or something, but when the grower mixes his own 

 lie can find no fault with the mixture as he made it 

 himself. 



