196 THE BOOK OF THE ROSE CHAP. 
the enemy are sure to have escaped: a close ex- 
amination the next day is necessary, and often a 
second application may be desirable. 
When the blooms are just ready to open we may 
take a hint from Nature, and, remembering that 
Roses in the open, especially H.P.s, are far better 
when a dull cooler day follows after some hot 
weather, endeavour to shade the plants from the 
full sun, and keep them, if possible, a little cooler. 
If a light blind be used, or the glass roof be syringed 
on the outside with a mixture of whiting and milk, 
or some similar clouding material, the flowers will 
be brighter, more lasting, and altogether of better 
quality. 
Ventilation is a most important matter in all forms 
of Rose cultivation under glass: the foliage is very 
tender, and a cold draught is almost sure to bring on 
mildew. Itis far better to give no air at all than to 
open the ventilators to an icy wind. Still, Roses 
must have air, and there will be few days when it 
cannot be admitted on the lee side for an hour or 
even less. Where the plants are grown in beds in 
a cool house, air should be given as often as possible, 
and in increased quantities as the season progresses : 
the final removing of the roof or top lights, after the 
plants have bloomed once, should be arrived at by 
gradual and easy stages, so that as little check as 
possible may be felt when all covering is taken away. 
As an early second crop of flowers may be expected, 
and a third from some of the freest sorts, especially 
of Teas, it is necessary that the feeding and culti- 
vation of the soil should not be forgotten, or the 
plants neglected because the outdoor Roses claim so 
much attention. Some ofthe weaker shoots may be 
