On Sat, 25 Oct 2008 00:04:48 +0000 (UTC), Jeßus
wrote:

Hi All,

I have a couple of young Silver Birch trees, still in pots.

After doing a search, I'm still not completely sure of what spacing I
should use when planting... I'd like to plant one either side of my main
front gate (I'm on acreage in Tasmania).

Plenty of sites state that max size is around 20m high x 10m wide, and
that the tree is "short lived". I'm not sure what their definition of
"short lived" is though? Also, approximately how many years are we
talking about when it comes to reaching full size?

I figure if the trees take 10-20 years to get near full mature size, that
I could plant them a bit closer, and I'd have plenty of time to prune/
train branches away so they don't reduce clearance through the gate.

So... what spacing would be best under the circumstances?
They will have full sunlight, the soil is pretty good, well drained with
plenty of organic matter (but I don't know the PH as yet).

I have plenty of compost, chook poo and a bag of dynamic lifter available
to feed the trees. I want to provide optimal conditons for growth, so if
there is anything else I should add, I'd be interested to know.

I suspect that some of the local critter might find the young foliage
tempting, so plan use stakes & chicken mesh for protection.

Having only known tropical horticulture, I'm on a bit of a crash course
learning all about temperate zone trees and plants in general... thanks
for any help.

How big they grow depends on temperature mainly. A grove in Iceland
has hundred year old trees that wouldn't reach the ceiling of a room.
Yet one I saw planted in Sydney said 'thanks a lot' and raced up to
the height of the single storey house in no time.

There probably won't be any creatures to blight the tree, given it is
exotic.

As for pruning, the essential beauty of a Silver Birch is in the
tracery of its branches. Pruning would destroy that appearance.

http://www.hainaultforest.co.uk/5Silver%20birch.htm

Space them by 10 m so each one can form properly.