In article ,
Sacha wrote:
On 2009-10-14 22:47:32 +0100, Malcolm said:


At the risc of being flamed for hi-jacking this thread, the school
where I work part time has had 3 (soon to be 5) planters installed 1000
x 1000 x 700deep) which I have been told will be planted with 'trees'
The planters are in a large (tennis court+) internal quad surrounded
with single story buildings with a high pitched roofline. I know that
there will be major watering problems but I am assured that 'the
children will do that' (& come in during the 6 week summer break?) The
planters have been filled with qua good quality soil/compost mix and
stand on a tarmac base.

I have ideas such as Acer, Mountain ash etc. Does the panel have any
suggestions?

Yes, it's a rotten idea, IMO. They won't get watered properly but will
get 'drowned' every so often and allowed to stand in wet compost or to
dry out entirely in between. Either a groundsman is going to tend them
properly or the money might as well be thrown away now. And as for
'trees' being planted in such a way - well, good luck to both the trees
and the tarmac, IMO! Do the people intending to plant these trees
realise that - as a rough rule of thumb - roots go as deep as a canopy
spreads?

Yes, and Acer and mountain ash are particularly unsuitable. Most of
the former really do not like drying out, and the latter handles
that by running its roots deeply. Sorry.

There are plants that will handle such conditions, such as (you may
laugh) pomegranate. It may drop its leaves when it dries out, but
it won't die - and it's surprisingly hardy. But it's not really
much of a tree, though it's a nice shrub. There may be some trees
from that sort of terrain that can survive drying out, but I can't
think of any offhand.


Regards,
Nick Maclaren.