Silver Birch

I have a Silver Birch in our garden its about 20 feet I was wondering if I could take out the top 5 feet, Has I don't want it to get to large, when is the best time to do this ?

 

Id suggest end of jan/early feb. The sap will still be going back to the roots right now so not now.
The side branches will grow quicker after the top has been removed giving a wider shorter tree. There will be lots of bushy new growth also from the trunk and branhes to make up for the bits chopped off.
Dont seal the wounds let it bleed out so minimising infection.
Thats my experience with topping our birch anyway.

 

I'd do it any time now, I dont believe the sap actually goes back to the roots, sorry @WeeTam

The sooner you do it, from now on the less chance of it bleeding next spring, which is not, IMO,a good idea, ask any one who has grown grapes.

 

But Birch sap surely 'rises' in spring because that's when it can be tapped and used for winemaking.

I've got quite a few SBs, mainly coppiced for pea stick production, although I've got at least one that I've topped (needed a length of trunk of a precise diameter), but sure I've read that pollarding SBs is not a good idea, can't remember reasons why so will have a look at that tree tomorrow.

 

All trees have the sap rising in spring, it goes back to the roots all summer, by now its not going back anymore, the tree is shutting down.
I agree, but the amount of sap taken needs to be controlled in order to not weaken the tree too much.
Lots of cut branches oozing sap uncontrolled, in spring, will, I'm thinking have a bad effect on the tree long term.

 

thanks for all the replys will give it a try and see what happens