84 MANAGEMENT OF THE FORCING-HOUSE, 
growing tomatoes, the plants become sappy and con- 
gested under such treatment, and may actually contract 
the dropsy, as is shown in the chapter upon tomato forc- 
ing. In a spell of dull weather in winter, the gardener 
must be particularly careful to keep his houses dry and 
sweet, for then the mildews develop rapidly. 
The houses should be kept sweet and clean. All trim- 
mings from the plants should be carried out of the estab- 
lishment. The soil should be changed every year, particu- 
larly on benches (as explained on page 51). If there 
have been serious infections of fungi or insects, the 
framework of the house should be painted during sum- 
mer, or else sprayed or washed with kerosene. Care 
should be taken to avoid filling the benches with in- 
fested soil. It is always safest not to select soil from 
fields which have recently grown the same kind of crops 
which it is desired to grow in the house; and if the 
forced plants have been badly infected, the soil in which 
they are grown should not be used again for forcing pur- 
poses. 
All possible precautions having been taken, the gar- 
dener may next exercise himself to devise means of kill- 
ing the pests. For aphis and the like, he will fumigate 
with some tobacco preparation ; for mealy-bugs he will 
use a fine hard stream of water from a hose, a_ proceed- 
ing which will greatly upset their domestic affairs ; for red 
spiders and mites he will syringe the foliage thoroughly 
with water above and below on all bright days; for mil- 
dews he will evaporate sulphur or dust it on the plants; 
for rusts he will spray with Bordeaux mixture; for damp- 
ing-off (and ‘‘canker’’ at the root) he will dry off the 
surface of the soil and mix a little sulphur or charcoal 
into it ;* for the nematode or root-gall (the work of which 
*See Atkinson’s monograph of damping-off, Bulletin 94, Cornell Exp. 
Sta. (now out of print), for an account of the various fungi concerned 
in the trouble. The advice which Atkinson gives for the treatment of 
