1606 



HOTBEDS 



HOTBEDS 



1912. Hotbed with movable frame. 



is made, concrete piers about 6 inches square should be 

 built every 6 feet for the wall to rest upon. They should 

 extend nearly 2 feet below the wall. The walls of the 

 excavation will serve as a form for the piers and if care 

 is taken in making the excavation for the wall itself, 

 there will be no need of making a form for the outside of 



the walls below 

 the surface, but 

 plank should be 

 set up for the in- 

 side of the walls, 

 and for both sides 

 of the wall above 

 the surface. For 

 making the grout, 

 use four parts of gravel, two parts of sharp sand and one 

 part of cement. Mix the sand and gravel and then 

 after adding and thoroughly mixing the cement, pour 

 on water enough to make a "wet mix." Pour the grout 

 into the form, thoroughly packing it, and then allow the 

 form to remain until it has set. 



Hotbed sash. 



The size that has been found most satisfactory for 

 hotbed sash is 3 by 6 feet, as when larger than this they 

 are not readily handled by one man. While pine and 

 other native lumber may be used, cypress is generally 

 perf erred, as it is much more durable and costs but little 

 if any more than clear pine. The sides and upper ends 

 of the sash are made from 3 by 1 J^-inch strips, grooved 

 to receive the glass, while the lower end is about 1 by 

 5 inches. The center strips are 1 by 1^ inches. For 

 glazing hotbed sash, single-strength 10 by 12 glass is 

 commonly used, as three rows of this size will fill a sash 

 3 feet wide. While double-strength glass will be less 

 easily broken, the increased weight is an objection to 

 its use. The use of double-glazed sash is often advised, 

 but aside from the extra cost, it will be found that the 

 sash will be heavy to handle and, if used near where 

 soft coal is burned, the bottom rows of glass will soon 

 become nearly opaque and it will be necessary to re- 

 glaze the sash in order to wash the glass. Where there 

 will be no trouble from soot and the sash is to be used 

 for the covering of half-hardy plants in the winter, 

 double-glazed sash may be used with satisfaction. 

 The sash should receive two coats of paint, and after 

 the glass, which may be either lapped or butted, has 

 been set, it should be given a third coat. 



Mats and shutters. 



For covering the frames on cold nights during the 

 winter and early spring months, straw mats are often 

 used, although those made of burlap are generally pre- 

 ferred. The burlap may be either single or doubled, 

 or it may be stuffed with straw, excelsior or other 

 materials. Quilted mats filled with combination wool 

 are very warm and quite durable. During the winter, 

 wooden shutters are also desirable to place over the 

 mats, as they assist in holding the heat, and by keeping 

 the mats dry, aid in preserving them. 



Heating material for hotbeds. 



To provide heat for the beds decomposing horse- 

 manure is generally used. While a large amount of 

 straw is not desirable, the presence of urine-soaked 

 bedding with the manure to the extent of one-third 

 its bulk is not objectionable, as it will lengthen the 

 heating period of the manure. Unless straw is mixed 

 with the manure, it will be well to add forest leaves to 

 the amount of one-third to one-half the amount of the 

 manure. The heating material should be forked over 

 and placed in a pile 5 to 6 feet wide, 3 to 4 feet high and 

 of any desired length. If the manure and straw are dry, 

 it will be well to moisten them with a fine spray. In 

 case there is but a small amount of manure, it will be 

 best to use warm water, though in all cases the soak- 



ing of the manure should be avoided. Within four or 

 five days the giving off of steam will indicate that heat- 

 ing has commenced. The pile should then be forked 

 over, working the outer portions into the center. 



The amount of heating material that will be required 

 for a hotbed will vary with the crop, as well as with the 

 location and season. For zero weather, there should be 

 at least 18 inches of heating material after it has been 

 well packed down, and 24 inches will be desirable in 

 midwinter in the northern states, while 6 to 8 inches 

 may answer where only a few degrees of frost are 

 expected. For 18 inches of manure, the excavation 

 should be made to a depth of 28 inches below the level 

 of the south side of the frame, and 31 inches below that 

 of the north side. After the manure has warmed 

 through for the second time it should be placed in the 

 excavation, spreading it evenly and packing it down 

 with the fork, but leaving it for a few days before 

 tramping it. Care should be taken to have the corners 

 well filled, that an even settling may be secured. After 

 the manure has again warmed up, it should be thor- 

 oughly tramped. 



The bed is then ready for the soil, which should be 

 quite rich and contain a large amount of sand and 

 humus, a compost of decomposed pasture sods with one- 

 third their bulk of rotten manure being excellent for the 

 purpose. The thickness of the soil should vary from 5 



1913. Hotbed in cross-section. 



to 7 inches, the greater depth being desirable for 

 radishes and other root crops (Fig. 1913). When boxes 

 of plants are to be placed in the beds, the depth of soil 

 need not be more than 3 inches. For a few days the bed 

 will be quite warm, but when the temperature of the 

 soil has dropped below 90 the seeds may be sown or 

 the plants set out. 



In severe weather the mats and shutters should be 

 placed on the bed at night and should be removed in the 

 morning. When the sun is shining, or if the bed is very 

 hot, it should be ventilated by raising (Fig. 1914) 

 or slipping down (Fig. 1912) the sash, the amount 

 depending upon the season and the condition of the 

 bed. By the middle of the afternoon the sash should be 

 closed and the covering should be replaced before night. 

 When used in the winter time, the hotbed should be 

 either sunk in the ground or well banked up with soil 

 or manure, so as to keep out the frost. 



Fire-heated hotbeds. 



Especially if the beds are to be used during the win- 

 ter months, and where there is an abundance of wood 



for fuel, it is advisable 

 to use artificial heat for 

 hotbeds. The simplest 

 and cheapest method of 

 heating is by means of 

 hot-air flues. These do 

 not differ materially 

 from greenhouse flues 

 except that they run 

 underground and 6-inch 

 sewer-pipe is used for 

 them. The best results 

 are obtained when the 

 beds are built on the 

 ?lope of a hillside> as this 



1914. Ventilating the hotbed. improves the draft. A 



