Winter-killing 



25 



been run on either side of the row. The posts are hinged 



by a pivot to a short post, and are held in position by 



a brace. The entire trellis is then laid down upon the 



approach of winter, as shown in the illustration. The 



blackberry tops are so strong that they hold the wires up 



from the ground, even 



when the trellis is laid 



down. To hold the 



wires close to the earth, 



stakes are thrust over 



them in a slanting 



position. The snow 



that drifts through the 



plants ordinarily affords 



sufficient protection for 



plants which are as 



hardy as grapes and berries. In fact, the plants may be 



uninjured even without cover, since, in their prostrate 



position, they escape the cold and drying winds." 



Severe cold is not the only cause of winter-killing. Other 

 weather conditions play an important part. In Nebraska, 

 red raspberries and blackberries are commonly killed to 

 the ground if left unprotected, and black-caps fare only 

 slightly better. Yet the climate is no colder than in New 

 York or Pennsylvania, where protection is rarely given. 

 During one winter in Nebraska, the mercury fell below 

 zero but once, and then only five degrees below, yet un- 

 protected canes were entirely killed. Young plants of 

 Taylor blackberry were uniformly killed to the ground 

 during that winter. Plants in adjoining rows, of the same 

 age and similar in other respects, were laid down and cov- 



Fig. 4. Laying down trellis-grown black- 

 berries. 



