544 On the Cidtivatioji of Grape Vines in Greenhouses. 



weather. This temperature will be advantageous to gerani- 

 ums, fuchsias, &c., at this season. When the mornings are 

 frosty in this month, the thermometer in the greenhouse is 

 generally down to 45° or 46° with me. I have had it as low 

 as this even when the grapes were in flower, and I have 

 never observed that they sustained any injury by this low 

 temperature. As the season advances, of course the heat 

 ought to be increased to 55° or 60° at night, and to 70°, 75°, 

 or 80° during the day. 50° and 55° at night, may be safely 

 taken as a general rule, for the first and second month's 

 growth. Air will be required, both night and day, at all 

 times when fire heat is necessary. In mild weather, in win- 

 ter, I give plenty of air during the day, and a small portion 

 at night also. 



No front air will be required in the early part of the season, 

 unless the weather is very mild. In summer, when the nights 

 are warm, a small portion of air should be left on all night 

 at two lights. If the temperature be low in the morning, 

 shut the house, and give no air till eight o'clock. It might 

 be sooner or later, according to the situation of the house. It 

 is impossible to lay down rules as to the time when air ought 

 to be given, or the quantity requisite at all times, nor is it 

 necessary, for this department of the business is snre to be 

 best performed by the person who keeps general principles 

 constantly in view, and not by him who is entirely guided 

 by written directions. It should always be remembered, that 

 heat should accompany light, and coolness darkness. 



Pruning. — I formerly recommended the long system of 

 pruning vines as best adapted to late vineries; but, as the vines 

 must be confined to the rafters in a greenhouse, in this case I 

 would advise the adoption of the spur system. A chief ob- 

 jection to this mode of pruning is, that in the course of time 

 the spurs get long and ragged ; but if the border is in tolera- 

 bly good condition, and covered as I have directed, the vines 

 will push vigorously from various parts of the old wood of 

 the spur, which may, therefore, be shortened as opportunities 

 offer. It is unnecessary to enter further into this department 

 of the subject, as the summer pruning and the preparation of 

 young vines for difierent plans of training, are generally un- 

 derstood by gardeners. 



