GRAPE VINES TEMPERATURES. 293 



at a temperature of 60, and that is as low as it ought to be used at any time. The 

 foregoing remarks apply to vine borders under glass ; but outside borders should also 

 receive due attention, watering them during the summer as needed, this being deter- 

 mined by the state of the soil. 



Temperature. At the start the temperature should be 50 at night, 55 by day, 

 advancing to 65 from sun-heat, as registered by a shaded thermometer. When the 

 buds swell, gradually raise the temperature to 55 at night, and 60 to 65 by day, and 

 when the vines are fairly growing increase the heat so as to have the night temperature 

 .60 by the time they are in leaf, 65 by day from fire heat, and 70 to 75 from sun. 

 Kaise the heat to 65 to 70 at night when they come into flower, 70 to 75 by day, 

 and 75 to 85 from sun heat. After flowering and setting let the temperature be 60 to 

 65 at night, 70 to 75 by day, and 80 to 85 or 90 from sun heat. It is at this stage 

 when the size of the berry is, in a great measure, determined ; for a good first swelling 

 in the short time elapsing between the flowering and the stoning helps immensely 

 towards large berries. Therefore, aim at a rise to 70 soon after daylight, and if the 

 weather is mild 5 more. With sun heat a day temperature of 80 to 85 should 

 be the rule, and a further rise of 5 or 10 after closing in the afternoon is admissible ; 

 also a little fire heat in the latter part of the day, to prevent the temperature falling 

 lower than 75 till within an hour of sunset, after which it should gradually decline 

 so as to reach the minimum about midnight. 



When stoning commences, about six weeks after flowering, or a fortnight sooner 

 in early varieties, the berries apparently cease swelling, and no good comes by 

 hurrying them ; therefore, keep the heat steady at 60 to 65 at night, 70 by day 

 without sun, but allow a rise of 10 to 15 from sun heat. Nothing is gained by early 

 closing so as to raise the temperature at this stage ; but in a month or less there 

 will be signs of renewed swelling, and early closing may be practised as before, till 

 the grapes show signs of colouring, when the early closing should be discontinued, 

 and the temperature gradually lowered after the fruit is thoroughly ripe. In the 

 case of early forced vines the temperature must not fall below 55 or 60 after the fruit 

 is cut, for a low temperature induces rest and the premature casting of the foliage, 

 which should be retained in a healthy condition as long as possible; otherwise the 

 vines may start into growth when they should be going to rest in September. In 

 the case of Muscats and thick-skinned grapes that are fully ripe in September, the 

 temperature may be gradually lowered to an even one of about 50, and this may 



