284 LUTHER BURBANK 



for forty years are made of redwood lumber. 

 Where this cannot be obtained, cypress is nearly 

 as good, but soft pine is not durable and should 

 be avoided. Eighteen inches square, outside 

 measure, four and one-half inches deep, inside 

 measure, is a good size. 



Two opposite sides are of common board lum- 

 ber three-quarters or seven-eighths of an inch 

 thick; the other sides are a little less than half 

 an inch thick. The bottoms are made of redwood 

 "shakes" which are about one- fourth of an inch 

 thick; two or more spaces of an eighth of an 

 inch being left for drainage. Across the bot- 

 toms are nailed three strips which add rigidity 

 and strength as well as affording better ventila- 

 tion and drainage. After all the parts are care- 

 fully fitted, the joints are sometimes dipped in 

 linseed oil before being strongly nailed together. 

 This gives durability and tends to prevent the 

 nails from rusting out. 



These redwood boxes may be used for many 

 years if sterilized once a year by being placed for 

 about three or four minutes in boiling water. 



A suitable soil is the first requisite in raising 

 seedlings in boxes. The mixture which I have 

 generally found best for use in the early winter 

 for raising seedlings in boxes in the greenhouse, 

 is compounded about as follows : One-half clean, 



