[Grubbypaws]

I need to prune my birch which is threatening to take out the telephone line. I quickly popped on line to find out when i could do this but   

One site said ' Most landscapers prune trees just before they break dormancy in late winter or early spring, but this timing doesn't work for birch trees. They bleed a heavy flow of sap if pruned when awakening from their winter rest, so the best time to prune birch trees is late summer or early autumn'.

The next site said ' Prune only in the winter or earliest days of spring while it is dormant, to remove dead branches identified in the fall'.

AAAgh!

Can anyone help?
   

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[New shoot]

They are one of the earliest trees to break leaf, so the advice is contradictory but sort of makes sense.  Late summer/ early autumn or winter/the very earliest spring days are all times when the sap would not be rising. 

If you prune late summer/early autumn you deprive the tree of the nutrients it would reabsorb from those leaves before they fell.  If you left it until spring and we got a mild spell, the tree might suddenly burst into life and bleed sap from the wounds.  I'd split the difference and prune after leaf fall, but get the job done before mid-Feb