UKTC Archive

Re: Green roofs and overhanging trees.

Subject: Re: Green roofs and overhanging trees.
From: Bill Anderson
Date: Oct 27 2020 14:32:37
The client's problem (or non-problem?) is being told to rake the leaves off
twice a year. I thought the answer would be to stick a ladder up and then
just blow the things off with a leaf blower, but then would that blow the
plants themselves off? I suspect there's a potential problem in that they
might have to get a contractor in (how many households have space to keep
ladders these days?) and if it's twice a year it starts to look expensive
for someone who thinks they're just doing it to satisfy a Council-generated
whim.
And would a dense mulch of leaves on an area where there are no lurking
worms to help get rid of them be quite as straightforward as a mulch in a
lot of grass? Do green roofs have worms? And for that matter, do leaves
actually accumulate on flat roofs? Or does the elevation mean they get
blown off more than might be expected?
Questions, questions....
Bill.

On Tue, 27 Oct 2020 at 11:45, Tahir Sharif <tahir@xxxxxxxxxxxx.org> wrote:

Green roofs come in all sorts, some are a system with various membranes
and u substrate over which a preplanted/seeded mat is rolled outn others
are a loose substrate that has been seeded or planted. Our roof isn't
near any trees but still gets a few, I can't see it would be a problem
personally but I guess a lot depends on the owner.

Tahir

On 27/10/2020 11:33, Rupert Baker wrote:
Hi Bill,
I'd have thought that a mulch of leaves would be useful for the
continuing health of a green roof - assuming that the substrate on which
the Sedum or WHY plants they are using is something that earthworms and
other soil biota can survive/flourish in...
I imagine that the complaint if that is what it is relates to the
quantities of leaves, possibly suppressing the greenery? - never mind, the
winter gales will thin the numbers down.
When I was with a local authority, one of our parks - centre-urban,
shrub-beds with trees round outside, grass in middle, lots of big Planes
and Limes - 25-30m+ x 80-100 dbh - used to get covered in leaves in
autumn/winter - one would get complaints from dogwalkers etc about
untidiness and mud; and the grass would largely disappear.
Next spring, back it came.
And that was on a fairly artificial surface; like many of the parks it
had been a municipal waste tip, with an incinerator at one end - 'nice'
smoke drifting down the valley - (talking late 19thcentury here) before
having a skim of soil over the glass, clinker, tins and carcinogens, and
becoming landscaped as a park. Various anoraks amongst the parkies had a
lovely time 'bottling' and selling or displaying the old bottles they
excavated whilst 'digging over the shrub border'
So I'd suggest to the owner not to panic; as long as it has a decent
substrate, and doesn’t bake hard and dry in summer, it should be fine; the
ones I've seen often look a bit patchy after a few years; they are not an
install and forget option, but need regular tickling of one sort or another

Atb
Rupert

-----Original Message-----
From: uktc-request@xxxxxx.tree-care.info On Behalf Of Bill Anderson
Sent: 27 October 2020 10:08
To: UK Tree Care <uktc@xxxxxx.tree-care.info>
Subject: Green roofs and overhanging trees.

What ho.
Just had a query from a client along the lines of what do I know about
green roofs? Apparently they've been told to rake the fallen leaves off
twice a year.
I have absolutely no knowledge of this topic so was wondering if anybody
else had. Especially as green roofs are becoming more common and even a
requirement on some developments.
I think in this case there's potential for an argument about a street
tree, and of course it's in the heart of Sheffield's protest area, but it
seems there might be another potential clash between trees and a planning
policy.
I'd be interested to hear of anyone's experience.
Thanks as ever,
Bill.



--
The UK Tree Care mailing list
To unsubscribe send mailto:uktc-unsubscribe@xxxxxx.tree-care.info

The UKTC forum is supported by Bosky Trees arboricultural consultancy
and Stockholm Tree Pits https://www.stockholmtreepits.co.uk








--
The UK Tree Care mailing list
To unsubscribe send mailto:uktc-unsubscribe@xxxxxx.tree-care.info

The UKTC forum is supported by Bosky Trees arboricultural consultancy and
Stockholm Tree Pits
https://www.stockholmtreepits.co.uk




-- 
The UK Tree Care mailing list
To unsubscribe send mailto:uktc-unsubscribe@xxxxxx.tree-care.info

The UKTC forum is supported by Bosky Trees arboricultural consultancy and
Stockholm Tree Pits
https://www.stockholmtreepits.co.uk