On Wed, 29 Oct 2008 10:38:09 +1100, Richard Wright wrote:

On Mon, 27 Oct 2008 21:56:16 +0000 (UTC), Jeßus
wrote:

On Tue, 28 Oct 2008 06:21:46 +1100, Richard Wright wrote:

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

Thanks for the advice Richard.

Turns out that two of the three seedlings I have are 'Pendula' - I am
under the impression that this variety grows somewhat smaller? Anyway, I
planted them 3.5m either side of the gate posts. So they're easily 10m
apart.

I also need a windbreak along one fence line and now I'm considering
using Silver Birches as the main tree for this as well - they should
help block the wind but not overly block the view excessively. Plus,
they look fantastic come winter time of course!

Cheers

I don't think SIlver Birch would be any use as a windbreak. The foliage
is not dense enough in summer. There is no foliage in winter, because it
is a deciduous tree.

I did consider that, but most wind breaks down here (Tas) seem to be
deciduous for some reason.