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 



