GRAPE GROWING IN GREENHOUSES 119 



all the bedding plants and Chrysanthemums. Kindly advise me as 

 to the best time to clean the house. No. 53, Bucks. 



A. It is quite safe to sulphur the hot water pipes in a vinery in 

 which the Grapes are ripe, provided it is not done excessively, other- 

 wise there is danger of injuriously affecting the skin of white Grapes 

 such as Muscat of Alexandria, White Frontignan, and indeed all white 

 varieties, the fumes taming the skin to a bluish colour, and to some 

 extent detracting from their appearance. But as you say there are 

 a number of Maidenhair Ferns and other plants in the house, it would 

 not be safe to use the sulphur on the hot water pipes, as the fumes 

 will certainly injure the more tender of the growths and cause them 

 to become brown. The better plan would be to use a sponge and go 

 over the leaves carefully, the sponge being moistened with a soft soap 

 solution, 2 oz. or 3 oz. soft soap to 1 gallon of water, and thus break 

 up the webs and remove most of the pests by the process. This is a 

 tedious but a sure way of palliating the evil, and would be the best. 



Rust on Muscat Grapes 



Q. Enclosed is a sample of Muscat of Alexandria Grape, being the 

 first fruit of a four year old Vine with an outside border. The 

 Vines were started in the first week of February. The brown marks 

 on the Grapes were noticed about a fortnight ago (August). 

 JZnquirer, Newbury. 



A. The Muscat of Alexandria Grapes are affected by rust. Over- 

 heating of the pipes while the berries were small would cause the 

 mischief. If the roots of the Vines are in a cold border, this condi- 

 tion of affairs would be aggravated ; violent changes in the tempera- 

 ture are also likely to predispose the Vines to this malady. 



Yine Leaves Diseased 



Q. Can you tell me what is the matter with the Vine leaves 

 enclosed ? They seem in a bad way. What can I do to cure them ? 

 A.E.T., Bury. 



A. Your Vines are suffering from a bad attack of thrips, red 

 spider and mildew, and if these pests are not speedily destroyed you 

 stand a very poor chance of getting any useful returns from your 

 Vines. Amongst the 'chief causes of attack from red spider and 

 mildew are the following : Over cropping the Vines in previous 

 years ; insufficient thought and care in ventilating, especially in 

 spring and early summer ; dryness at the roots, and a too close 

 proximity of the foliage to the glass in hot weather. The cause of 



