Re: Hibiscus syriacus looking sad
- Subject: Re: Hibiscus syriacus looking sad
- From: &* a* M* <t*@xtra.co.nz>
- Date: Mon, 11 Aug 2008 10:56:12 +1200
Tony & Moira Ryan,
Wainuiomata,
Central New Zealand
----- Original Message -----
From: Pamela Steele
To: Medit-Plants
Sent: Sunday, August 10, 2008 12:44 AM
Subject: Hibiscus syriacus looking sad
This year my Hibiscus syriacus is not looking at all wonderful. It is an
unknown variety 'double white' about 4 meters in height and was here when we
purchased the property four years ago. Many of the leaves are quite yellow
and have been since April. The flowers are smaller than usual and they are a
bit sparse and there are quite a few dead unformed buds which duly fall off.
It has never been pruned because I thought it didn't need it. I have given
it water and two doses of iron since April. My neighbours' single blue
looks really well with dark glossy leaves and prolific blossom. I have an
number of large mature H.rosa-sinensis and they all look fantastic. Any
ideas what I am doing wrong?
Pamela
It is quite possible your bush has contracted some sort of root disease in
which case you will probably have to face its demise, but if it is now
getting quite old it could be simply loosing vigour as I understand shrubs
of this variety are inclined to do. An old NZ book of mine by a wise
nurseryman whose opinion I trust suggests that some old bushes my revive if
cut down to "a few feet". I would translate this to maybe halving the height
of your ailing friend next winter while it is dormant and seeing if you get
vigorous new growth. At the same time as it has been in the same place for a
good while I wonder if it needs some actual feeding, as distinct from the
iron treatment, and would benefit from a good "meal" of compost or shredded
young wood *or even just bark spread over its root zone. Always avoid
putting such mulches hard against the stem, but leave a small gap round the
plant.
Moira
* modern research has found that the very best slow release food for trees
and shrubs is shredded ramiel wood. This is basically shredded tree prunings
from healthy subjects which are no more than a couple of centimeters in
diameter and are still rich in green and growing tissue. The sort of wood
one which will go through the average garden shredder is ideal.
