116 ON FORCING VEGETABLES. 



Perhaps the safest time to commence forcing in frames, 

 is soon after the middle of February, and the early part of 

 March. I before hinted, that the depth of heating materials 

 must be regulated by the season of the year at which the 

 work is commenced, and also to the purposes for which the 

 hot-beds are intended. Beds used for the purpose of raising 

 half-hardy plants, or for procuring seedling plants late in the 

 spring, may be made in the manner recommended for the 

 common hot-bed ; but if substantial heat is required to be 

 kept up, the beds must be so contrived as to admit of linings 

 as the heat decreases ; and the dung should undergo a regu- 

 lar process of preparation, according to the use it is intended 

 for. Compost heaps should also be provided, in order to 

 furnish suitable mould to the different species of plants ; for 

 this purpose, all the old hot-bed dung and mould, leaves, tan, 

 turf, sand, and other light manures and decayed animal dung, 

 should be collected together. 



In some cases, when a slight hot-bed is recommended for 

 forwarding hardy plants, if it should happen that a seedling 

 Cucumber bed be at liberty, it may answer every purpose 

 for Radishes, Lettuce, or other hardy plants ; or such a bed 

 may be spawned for Mushroons, if required. 



If the forcing be commenced before the coldest of the 

 winter is past, great precaution must be used, lest the plants 

 be injured by cold cutting winds, or destroyed by heat for 

 want of air. To prevent the former accident, warm dung 

 should be placed around the frames, and the sashes covered 

 with mats and boards every night. If full air cannot be ad- 

 mitted in the day time, the sashes must be slidden down to 

 let off the steam ; at the same time mats may be laid over 

 the aperture, to prevent cold air entering to the plants. 



If the bottom heat in a bed be too violent, which is some- 

 times the case, means must be used to decrease it. This is 

 generally effected by making holes in the bed with a stake 

 sharpened at the end, or with a crow : bar ; which holes should 

 be filled up when the heat is sufficiently reduced. In lining 



