FREEZING TEMPERATURES 



11 



often the case with less hardy plant material. Asparagus plumosus 

 foliage, which is shipped in considerable quantities, also froze at a 

 relatively low temperature, 24.2°. The leaves of sansevieria plants, 

 which are frequently shipped in large quantities for potting as orna- 

 mentals, froze at the relatively high temperature of 31.0°. Among the 

 bulbs studied, tulips froze at 25.4°, and Paper White narcissus froze 

 at close to 29°. 



Table 5. — Average freezing point of certain cut flowers, bulbs, corms, tubers, and 



plants 



Kinds 



Cut flowers (petals): 



Anemone 



Carnation 



Chrysanthemum 



Columbine ' 



Daisy, Shasta i 



Delphinium ' 



Gardenia 



Gladiolus 



Heath (heather) 



Hemei'ocallis ' 



Hyacinth 



Iris (Japanese) 1 



Lily, Easter 



Narcissus, Sir WatMns 



Orchid (Cattleya) 



Peony 



Poinsettia 



Ranunculus 



Rose, hybrid tea 



Tulip 



Violet (sweet) 



Bulbs, corms, and tubers: 



Dahlia 



Gladiolus 



Hyacinth 



Lily, Calla 



Lily, Regal 





Extremes 





Av- 

 er- 















age 



Min- 



Max- 







imum 



imum 





F. 



° F. 



° F. 





28.1 



28.0 



28.2 





28.4 



27.9 



28.7 





28.4 



28.0 



28.7 





31.1 









29.3 









26.6 









28.3 



28.3 



28.3 





28.7 



28.7 



28.7 





28.7 



28.7 



28.7 





30.8 









28.7 



28.5 



29.0 





30.5 









27.5 









30.1 



30.0 



30.9 





30.8 



30.1 



31.1 





29.0 









29.2 



29.0 



29.5 





28.6 



28.2 



28.9 





30.0 









28.0 



27.7 



28.2 





28.5 



28.2 



28.8 





28.3 



28.0 



28.7 





26.8 



26.5 



27.0 





28.7 



28.5 



29.2 





27.5 



27.5 



27.5 





27.1 



27.0 



27.8 





Kinds 



Bulbs, corms, and tubers— Cont 

 Narcissus, Paper White: 



Dormant 



Sprouting 



Narcissus, Sir Watkin 



Tulip 



Plants (foliage): 



Amaryllis ' 



Asparagus plumosus 



Aspidistra ' 



Caladium, fancy leaved *__ 



Carnation 



C hr y santhemum 



Columbine • 



Daisy, Shasta 



Delphinum • 



Dracaena • 



Fern, Oregon Dagger 



Gladiolus ' 



Hemerocallis ' 



Holly, eastern grown 



Iris. Japanese l 



Lily, Easter 



Pandanus ' 



Peony 



Rose, hybrid tea 



Rubber, variegated i 



Sansevieria laurentia 



Vinca major • 



Violet (sweet) 



F. 



29.4 

 26.1 

 25.4 



31.0 

 24.2 

 24.9 

 30.6 

 27.4 

 29.6 

 29.1 

 30.0 

 29.2 

 28.0 

 23.6 

 26.8 

 30.0 

 26.3 

 28.7 

 29.2 

 30.4 

 28.4 

 28.3 

 30.3 

 31.0 

 28.6 

 27.4 



Extremes 



Min- 1 Max- 

 imum imum 



28.2 

 29.1 

 25.8 

 24.9 



23.5 



27.4" 



28.7 



23.6 

 26.8 

 30.0 

 23.9 



29.3 

 29.9 

 26.3 

 25.4 



27.4 

 30.5 



23.6 

 26.8 

 30.0 

 27.0 



Data furnished by T. M. Whiteman. 



SUMMARY 



Freezing or freezing injury does not always occur when fruit or 

 vegetable products are exposed to temperatures at or below their 

 actual freezing points. Under certain conditions many of these prod- 

 ucts can be undercooled; that is, cooled to a point below the true 

 freezing temperature of each and again warmed up without freezing 

 and without apparent injury. Certain products under certain condi- 

 tions may be actually frozen and afterwards thawed out without 

 apparent injury, while, on the other hand, some products are injured 

 by chilling if stored at temperatures well above their actual freezing 

 points. Evidence seems to show that different individuals of the same 

 variety and strain when grown under different conditions will have 

 somewhat different freezing points, and that there are also some vari- 

 ations in the freezing points of products of the same variety and from 

 the same lot. Sometimes this is due to different degrees of maturity. 



