THE VINE 219 



are most useful where grapes are required very early in the year, for usually being 

 built against a south wall they benefit more from sun heat, and are naturally 

 warmer than the span roof, which is exposed on all sides. The lean-to house 

 is also more easily fixed, and is cheaper than a span roof, provided that the wall 

 already exists. Those who are fortunate enough to possess a wall against which 

 a house may be built would, of course, be unwise not to take advantage of it, for 

 equally good grapes can be grown in a lean-to as in a span roof. The reason I 

 would recommend the latter where no special conditions exist is because (i) a 

 span roof is cheaper if a wall has to be built before the lean-to house can be 

 erected, and (2) it will hold twice as many vines as will a lean-to, and all possible 

 space is utilised. In the lean-to such is not the case, for the back wall is practi- 

 cally useless. Vines may be planted, and they will cover the wall with foliage, 

 and for the first few years, until the roof is covered by the permanent vines, will 

 give a small return in fruit, but not afterwards, in consequence of the absence of 

 light. The three-quarter span, or what is more commonly understood as the 

 hip roof, is self-descriptive. It answers for early forcing as well as the lean-to, 

 indeed better in some respects, and especially in that more light is admitted, 

 particularly in the afternoon and evening. It also gives a larger roof surface. 

 The disadvantage of this style of house is that it is more costly in construction. 

 Span- roofed houses are best for the successful production of mid-season and late 

 grapes. The ends of these should face north and south. Any one contemplating 

 covering an acre or two of ground with span-roof houses for the purpose of 

 growing grapes for market, I would advise first to visit one or more of our 

 best commercial grape-growing establishments. These are to be found in 

 many parts within a short distance of London, notably Finchley, Broxbourne, 

 and Worthing. Abundant facilities must be provided in order that the vines, 

 when at rest, may have as much air as possible ; and care must also be observed 

 that the ventilators are made air-tight. 



Heating. — Provide as many 4-inch pipes as will give sufficient heat to meet 

 all requirements in the coldest weather without the pipes being at any time very 

 hot. Nothing operates more against successful fruit culture in glass-houses than 

 overheated pipes. Naturally the number of rows of pipes laid down will depend 

 upon the size of the house, and whether it is intended for early forcing or only 

 for midsummer or late crops. If for the former, the houses should be compara- 

 tively small, and lean-to or three-quarter span. Six rows of 4-inch pipes should 

 suffice — four flow pipes and two return — the four placed within, say, a foot of 

 the front wall of the house (but quite 10 inches from the vine stems), and the 

 two returns in the middle of the house. Later houses will require less pipes in 

 proportion, but it is false economy to lay down insufficient. Valves must be 

 fixed in the flow and return pipes where these enter the house. 



Trellising for the Roof. — It is a common mistake to fix the trellis too 

 near the glass, thereby cramping the foliage, subjecting the leaves to injury from 

 disfigurement by sun, and also from extreme cold at night by contact with the 

 glass. From 18 to 24 inches should be allowed, according to the vigour of the 

 varieties grown. Wires one-fifth of an inch thick should be placed parallel 

 to the front of the house, at 1 2 inches apart. 



