412 THE GARDENER. [Sept. 



knowledge, been shown otherwise, and I think it is a pity they should 

 be invited at all before the end of July. But Hamburgs are just as 

 easy to colour in April as in September. They are not, perhaps, so 

 easy for everybody to grow in the winter months as they are in the 

 summer, but any person having grown them at any time of the year, 

 and brought them in good condition through the stage of stoning, the 

 question of colouring is then merely a matter of air and light acting 

 on a good supply of healthy foliage ; and I should not be afraid to say, 

 that if a house of Hamburgs were given over to me at this stage in a 

 moderately healthy condition as to foliage, that I could insure the 

 colouring of all such berries as would not shank. The process would 

 be a very simple one. I should first take great care that the quantity 

 of fruit was not in excess of the capabilities of the foliage. There can 

 be no rule laid down for this, as one good substantial leaf in full sun- 

 light is worth more than a dozen flimsy ones which are partially 

 shaded. What would be a heavy crop for one Vine where the plants 

 are close together might be a light crop for another where more space 

 is allowed. Next I should see that the border was never dry ; and 

 lastly, that the house was never without ventilation, unless for an hour 

 or two when a cold spell of wintry w^eather came on suddenly. 



" A minimum temperature of 65°, with a rise of 80" by sun-heat if 

 the fruit has to be hurried in ripening, and all the air continually that 

 these conditions will allow, without admitting a cold draught or neces- 

 sitating too much hard firing, is the treatment recommended. The 

 colouring cannot take place without a constant change of air. The 

 colder the outside temperature, the smaller of course must be the 

 aperture for ventilation, and in frosty or rough weather sufficient air 

 will often enter through the laps of the glass during nights and dull 

 days ; but this constant stream of fresh air, till we find some better 

 method at this particular stage, is an imperative necessity. When 

 Grapes of the Hamburg class are not forced, and there is no necessity 

 to hurry them, the simplest way to insure colouring is to leave them 

 open night and day. There is far too much opening and closing of 

 ventilators with most of us. 



" The thick-skinned Grapes, such as Lady Downes and Alicante, 

 which are intended to be kept through the winter for use in February, 

 March, April, and !May, require a higher temperature at this stage than 

 is necessary for Hamburgs, and they will do with a less amount of 

 ventilation when once the stoning process is over. The colouring of 

 this class of Grapes should commence at the end of July or the first 

 week in August, and a minimum of not less than 65° should be kept 

 for two months afterwards. If a little ventilation can be allowed all 

 night so much the better, but it is an absolute necessity to have some 

 before the temperature rises in the morning. 



"Muscats, to colour them well, require similar treatment to the 

 thick-skinned varieties; but there is this difference between them — all 



