`Killing Frost and Length of Growing Season in Kentucky 123 5
_ chances he takes from probable damage_ by frosts, both in V V  
. spring and fall. i » Q
Also, the farmer should know something of the length  
of the growing season, or the period of safety for plant growth, ¢
in his locality, which he can in the long run depend upon. The i
length of the growing season is usually considered to be the
, ‘ number of days in each season between the date of the last . i
» killing frost in spring and that of the first killing frost in fall. A
The length of a growing season considered 81 per cent. I
safe, that is, safe in the long run 4 years in 5, has been com- . ,,
puted for each station and results tabulated in Table 3. The   i
number of days practically sure and the range of probable days A li
given in the~table fora particular station may reasonably be    
taken as typical of the section in which the station is located.   I
Exi>L.xN.vr1oN AND P1z.xc*r1c.xL Usn or THE Timms. »  1
Table 1 gives, for each station, the computed probable   · t
latest dates of killing frost in spring, ranging from the average A i _  
date, when the risk is 50 per cent., to a date when the risk is  J. g
only 5 per cent. If, for example, one should want to know what .i_ I j
the risk is at Blandville, or say in Ballard County, for a kill-  ri __ A
ing frost in spring as late as April 15, he would End from the I ·i A
table that it is 33 1/3 percent., or 1 year in 3. If he should   A i
want to know the date the risk for the same locality would   V.  
be only 20 per cent., or 1 year in 5, he would find that date .   ,
` . to be April 18. If he should want to know the actual earliest   ·l T  
or the actual latest dates of the last killing frost in spring, on   _  
record at any of the stations, the information can be found in   1,
the last two columns. ‘   , l
Table 2 gives similar information as to the first killing   3  
frost in fall. ,    
Table 3 gives the computed length of the growing season i    
i for each station, which can be relied on 4 years out of 5. lf one dt    
should want to know the length of a growing season 81 per    
cent. safe from frost in both spring and fall, or practically S11I'€  
_ —l years in 5, at Blandville or vicinity, he would find it to be  
170 days. However, tl1e probabilities are (from same table)  
‘ that, 4 years in 5, the growing season will be as long as 133  
A  A . days, but not longer than 205 days. _  
The charts are self-explanatory.  
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