510 HORTICULTURE, FORESTRY, FLORICULTURE 



ordinary hotbed. First, there is no danger of breakage by the wind 

 and a consequent injury to the tender plants; second, it can be cared 

 for more easily and safely; third, more air space is afforded above 

 the plants with consequently less danger of sun-scald, and ventila- 

 tion is afforded; fourth, it can be heated; and fifth, it can be used 

 for storage purposes. (S. Dak. E. S. B. 47.) 



THE COMMERCIAL GREENHOUSE. 



The truck farmer who is raising flowers and vegetables for the 

 city market, and the beginner in flower culture may want to start 

 with a commercial greenhouse one which is not too expensive. A 

 nine by twelve metal frame house complete can be purchased for 

 from $80 to $115. A nine by twenty feet will cost about $250. The 

 lean-to type which is made to join the residence so that it can be 

 heated from the dwelling furnace is an economical and favorite type 

 with the farmer and truck gardener. 



After choosing a location which from the greatest number of 

 standpoints is desirable, make the excavation as detailed for the 

 country greenhouse so the end of the building is to the south. The 

 foundation to the surface should be of grout (sand, gravel and 

 cement) . The remainder of the wall should be preferably of two to 

 four thicknesses of boards, two of building paper and then an air 

 space. It is economy to buy only the best materials. All joints 

 should be rigid and waterproof. Be sure that the glass is double 

 strength and contains no burning pieces; it will mean economy in 

 fuel and save many of the plants from sun-scald. 



Hot water is considered the best heat, piped for both overhead 

 and underbench, with pipes one and one-half to two inches in 

 diameter which run between five and ten cents per foot. If it is not 

 convenient to heat with hot water, an inside oil heater can be used. 

 For the Northwest, where wide and sudden drops of temperature are 

 frequent, this is the advisable heat to use. The smoke flue should 

 be so constructed however that no gas escapes into the plant house. 

 An inside coal fire should never be used in the raising of flowers. 

 Practically all of the manufactured greenhouses can be fitted with 

 mechanical devices for ventilation at both eaves and comb. 



Accessories for the greenhouse are prepared earth and fertilizer 

 in bins, shallow propagation boxes, boxes four inches in depth for 

 large plants, one, two, three and four inch pots, a vessel for watering 

 the plants, a vessel in which to wash the pots, a drainage box, fumi- 

 gating materials, Bordeaux mixture, a spray, a trowel and a fork. 

 As far as possible the commercial greenhouse should be adapted to 

 the special crop to be produced and constructed with economy in 

 space, heating and cost. (Mich. E. S. B. 63.) 



GREENHOUSE SOIL. 



One of the most vital and important questions to the suc- 

 cess of growing plants under glass is the soil, for upon a proper 

 understanding of this depends in large measure success or failure 

 in the work. While science has done a great deal to advance our 

 knowledge of the relation of soils to the growth of plants, there yet 

 remains much to be accomplished in the practical interpretation and 



