108 THE POTATO. 



weather, so that the lights may be removed in the morn- 

 ings. After watering, close the lights for a time, unless 

 the sun is very bright, in order that there may not be a 

 serious fall in the temperature. If all goes well, the crop 

 ought to be ready for lifting in about eight weeks from the 

 time of planting, but, of course, much depends on the 

 temperature and the amount of sunshine. 



Potatoes in Heated Pits Where hot water is 

 employed as the heating medium, new potatoes may be 

 had from January onward. The beds should be prepared 

 in the same manner as previously recommended by the aid 

 of fermenting material, the difference being there will not 

 be such a bulk required, as the whole will be placed inside 

 the pit. When planting allow a distance of about fifteen 

 inches between the rows and nine from one set to another 

 in the row. If planted closer, the haulm is apt to become 

 overcrowed, and the results are seldom satisfactory. 

 There will be more evaporation in pits heated by hot water 

 than in hotbeds, where the temperature is maintained by 

 the heat of the fermenting material, therefore more water 

 will be necessary. Choose a fine morning when the exter- 

 nal temperature is favourable for watering, and always use 

 water a little warmer than the temperature of the soil, 

 say, from 75 to 80 deg. Fah. Ventilation will also need 

 great care, as potatoes will not thrive in a close, dry atmo- 

 sphere. When the haulm has grown about six inches long, 

 earthing should be done, for if this be deferred too long, 

 much injury will be caused to the foliage. In very cold 

 weather, when it is most difficult to ventilate, do not 

 allow the external air to come in contact with the young 

 foliage, as this often causes a check to the growth, the 

 foliage is attacked with aphis, and in a short time the 

 whole plants become infested with this troublesome pest, 

 causing the foliage to turn yellow and die off. 



Potatoes in Cold Frames. As early as February 

 potatoes may be planted in these with safety, the sets 



