Hello

I have a mature hibiscus (syriacus I think) which is giving me trouble, and
I'd appreciate some advice.

Some of the branches are coming into leaf later and later every year, and
are getting covered in what might be lichen. The problem is spreading and
now affects most of the plant, and I want to take some action to save the
rest of it.

I live in Cambridge, the plant's in full sun, but the soil is low-lying and
rather heavy, and sometimes gets waterlogged in winter. I've read that
hibiscuses don't like that, and wonder if it might be causing the problem.
Alternatively, could it just be poor watering? poor feeding? or simply old
age?

There are two other hibiscus plants nearby, which have a similar problem but
to a much lesser extent.

Do you know what the problem is? And what should I do about it? I'm a
newcomer to gardening, and would be very grateful for any advice you can
give.

Many thanks

Chris

In article ,
"Chris Cox" writes:
|
| I have a mature hibiscus (syriacus I think) which is giving me trouble, and
| I'd appreciate some advice.
|
| Some of the branches are coming into leaf later and later every year, and
| are getting covered in what might be lichen. The problem is spreading and
| now affects most of the plant, and I want to take some action to save the
| rest of it.
|
| I live in Cambridge, the plant's in full sun, but the soil is low-lying and
| rather heavy, and sometimes gets waterlogged in winter. I've read that
| hibiscuses don't like that, and wonder if it might be causing the problem.
| Alternatively, could it just be poor watering? poor feeding? or simply old
| age?

Firstly, ignore the lichen. It is completely harmless, and merely
indicates that the shrub isn't shedding bark.

Secondly, the problem is primarily the weather. Despite the fact
that we have been having very warm winters recently, we have also
been having very cold springs. That shrub comes from relatively
hotter and drier conditions (as its name suggests) and won't put
out leaves until the weather warms up. If you think that it has
problems, think of my poor Erythrina crista-galli, which has only
just got a 2" shoot :-(

The waterlogging may kill it, but there is little you can do about
that. I had a couple that were killed by something a decade or so
back, and you just have to replant with something else.


Regards,
Nick Maclaren.

In message , Nick Maclaren
writes

Secondly, the problem is primarily the weather. Despite the fact that
we have been having very warm winters recently, we have also been
having very cold springs. That shrub comes from relatively hotter and
drier conditions (as its name suggests) and won't put out leaves until
the weather warms up. If you think that it has problems, think of my
poor Erythrina crista-galli, which has only just got a 2" shoot :-(


Hibiscus syriacus is a misnomer; the wild range of the species is Korea
(where it's the national flower) and northern China. But it's
naturalised in quite a few warmer places. It comes from a more
continental climate, and according to the literature, requires the aid
of a wall to encourage flowering in the cooler-summered parts of the
British Isles. As it's very late into leaf I assume that it doesn't mind
cold springs.
--
Stewart Robert Hinsley
http://www.malvaceae.info/Genera/Hibiscus.html

In article ,
Stewart Robert Hinsley wrote:

Hibiscus syriacus is a misnomer; the wild range of the species is Korea
(where it's the national flower) and northern China. But it's
naturalised in quite a few warmer places. It comes from a more
continental climate, and according to the literature, requires the aid
of a wall to encourage flowering in the cooler-summered parts of the
British Isles. As it's very late into leaf I assume that it doesn't mind
cold springs.

Dammit - I shouldn't have assumed that "syriacus" meant "well, I first
saw it it growing from some miscellaneous seeds sent from a collector
who had been visiting Syria". Stupid of me :-)

At least it is better than Bermuda buttercup.

It doesn't. It grew successfully here for many years (and other
people grow it), until it succumbed to a fungus or similar. But it
really can't be bothered to wake up until the weather warms up, which
it hasn't done for more than the odd day this year.


Regards,
Nick Maclaren.

"Nick Maclaren" wrote after
Stewart Robert Hinsley wrote:

Hibiscus syriacus is a misnomer; the wild range of the species is Korea
(where it's the national flower) and northern China. But it's
naturalised in quite a few warmer places. It comes from a more
continental climate, and according to the literature, requires the aid
of a wall to encourage flowering in the cooler-summered parts of the
British Isles. As it's very late into leaf I assume that it doesn't mind
cold springs.

Dammit - I shouldn't have assumed that "syriacus" meant "well, I first
saw it it growing from some miscellaneous seeds sent from a collector
who had been visiting Syria". Stupid of me :-)

At least it is better than Bermuda buttercup.

It doesn't. It grew successfully here for many years (and other
people grow it), until it succumbed to a fungus or similar. But it
really can't be bothered to wake up until the weather warms up, which
it hasn't done for more than the odd day this year.

All 3 of mine are just about in full leaf now, and nice and dark green they
are too.

Changing the subject slightly did anyone else see the Hibiscus that they had
at RBG Kew last summer next to the Princess of Wales glasshouse. Huge dinner
plate flowers, the biggest Hibiscus flowers I've ever see and I've been to
many tropical places. Now last time I visited, about 3 months ago, I noticed
they haven't dug up the roots just pruned them down to ground level as if
they expect them to shoot again. Anyone know if they will/have and what
species or hybrid these plants were?
I might just be able to find space for one or two. :-)

--
Regards
Bob
In Runnymede, 17 miles West of London

In message , Bob Hobden
writes

Changing the subject slightly did anyone else see the Hibiscus that
they had at RBG Kew last summer next to the Princess of Wales
glasshouse. Huge dinner plate flowers, the biggest Hibiscus flowers
I've ever see and I've been to many tropical places. Now last time I
visited, about 3 months ago, I noticed they haven't dug up the roots
just pruned them down to ground level as if they expect them to shoot
again. Anyone know if they will/have and what species or hybrid these
plants were? I might just be able to find space for one or two. :-)


That's presumably Hibiscus moscheutos or one of its allies, hybrids or
cultivars. These are hardy herbaceous perennial hibiscus from North
America (H. moscheutos is native as far north as southern Ontario),
sometimes called "dinner-plate hibiscus". IIRC, the largest flowers come
from strains such as 'Galaxy', 'Southern Belle' and 'Dixie Belle'.
--
Stewart Robert Hinsley

In article ,
Dave Poole writes:
|
| Irrespective of its country of origin or the rather dated, syndicated
| information still appearing in some books, Hibiscus syriacus is a very
| tough and hardy shrub for growing in almost all of the UK. The
| Cambridge climate poses no problems whatsoever for it and its hybrids.
| In fact, I would have thought that the normally very sunny climate in
| Cambridge would suit it well. The slightly fleshy root system needs a
| well drained soil otherwise partial root rotting can take place. The
| plant should be exposed to full sun for as long as possible in order
| to ripen the wood for a good flowering. However it does not need to
| be planted close to a wall and is perfectly at home in a sunny open
| border.

Yes. It is fairly widespread around here, and my two were in just
such a border. They succumbed to something (a fungus, I think)
that also took out two buddleia, a cherry and a magnolia over a
period of 5 years. But you can see a fair number if you wander
around.

However, I think that (as with many such plants) it is likely to
be fairly short-lived in the UK climate, especially in wetter
conditions or when there are certain soil fungi present. I can't
keep rosemary or sage going for above 5 years or so, and some
thymes have trouble, too. Despite the soil being 60% sand!


Regards,
Nick Maclaren.

Thanks for your advice. I'm inclined to think that the problem's more than
just springtime laziness (part of the plant has been in leaf for 2 or 3
weeks now, but most of it hasn't started) - I'll go with waterlogged roots.

Chris