WINTER PROTECTION 



Cytisus Canariensis, unless the whole roof is glass. A 

 pit like this has always been used in the Arnold Arbo- 

 retum for wintering seedlings, rooted cuttings and 

 grafts, — young stock grown in flats but too delicate for 

 the open ground. The arrangement of shelves shown 

 in the diagram gives storage to large numbers of tliese 

 small plants. 



In No. 4 is shown a small plant cellar, more expensive 

 but with better capacity for large plants. It should run 

 north and south, and, excepting the glass roof, is wholly 

 below ground, and consequently extremely well protected 

 against frost. The door is at either end or side. By 

 taking advantage of sloping ground it is possible to 

 enter on the ground-floor level, which is important when 

 large plants in tubs must be handled. In such cases a 

 concrete floor may be built. The monitor roof provides 

 plenty of light and ventilation; wooden shutters cover 

 the glass in cold weather. This form of pit is not only 

 well adapted to plants, but also is excellent for storing 

 vegetables and fruits. The forms of buildings larger 

 than those above described vary much with different 

 circumstances. Sometimes the cellar of a stable, tool- 

 house or other outbuilding can be utilized. The chief 

 consideration is pro- 

 tection against frost, 

 but provision must be 

 made for thorough ven- 

 tilation, and against a 

 too high temperature 

 in the autumn and 

 early spring. It is be- 

 cause it is hardly pos- 

 sible to provide for 

 these matters that 

 dwelling-house cellars 

 do not make good pits; 

 they cannot be sufli- 

 ciently ventilated to 

 keep the temperature 

 low enough except in 

 the middle of winter. 

 Growth is incited and 

 cannot be maintained 

 owing to lack of light. 



Construction of the 

 P(7s.— Owing to their 

 position, pits cannot 

 well be made of wood, 

 plank and cedar posts 

 lasting from 4-6 years 

 only. For large pits, stone and brick are most eco- 

 nomical for walls and ceilings; for small ones concrete 

 probably makes the cheapest and best wall. At the 

 Bussey Institution the concrete walls of several small 



WINTER PROTECTION 



1983 



pits have stood 10 or 1 

 sign of deterioration. I 

 priced Portland cements 



2 years without showing any 

 is not necessary to use high- 

 because the structures are se- 



2738. Nurseryn 



A cheap device for wintering plants that require comparatively 

 little Ught. 



cured against frost by the winter protection required for 

 their contents. An excavation of the required dimen- 

 sions is made, with due allowance for the walls. Inside 



the 



of 



the walls, from the 

 walls of earth which 

 should have been cut 

 as true as possible. 

 This frame, which 

 should also be true and 

 plumb, is carried to the 

 required height for the 

 inside face of wall and 

 another frame is made 

 at the proper distance 

 on the surface of the 

 ground, the inner face 

 of which will be the 

 outside face of the 

 completed wall. These 

 frames must be well 

 braced; they carry a 

 heavy load until the ce- 

 ment hardens. It is 

 not necessary to make 

 a complete frame for 

 the whole pit at once; 

 one end and a half of both sides can be built first, and the 

 same frame reversed will serve for the remainder. The 

 concrete is made by mixing dry one part of cement (a 

 good brand can be obtained at about $1.20 per barrel) to 

 two parts of clean sharp sand. After a 

 thorough mixture, add enough water to 

 make a thidk paste. Add to this paste 

 three parts (sometimes four are used) of 

 clean gravel. Broken stone is better but 

 more expensive. No stones larger than a 

 goose egg should be used. The whole 

 should be completely and quite carefully 

 blended with hoe or shovel until each 

 stone is coated. Throw this mass into 

 the space between the molding frame and 

 earth wall and settle compactly with a 

 rammer. It is not advisable to mix more 

 than a barrel at once, nor so much as this 

 unless at least six men are employed. 

 Continuous batches are made until the 

 work is finished. When the top layers are 

 going in, insert %-\n. iron bolts 6-8 in. 

 long at intervals of sis ft. These secure 

 the wuoden sills. In warm dry weather 

 the frames can be removed within twenty- 

 four hours or less, but first examine care- 

 fully the condition of the cement. After 

 removal, smooth off any roughness and 

 grout in with a whitewash brush a coat of 

 l*ortland cement mixed with water, but 

 without sand, thus obtaining a good color 

 and a more homogeneous .surface. For 

 several days the work should be shaded 



