Re: rust never sleeps
- Subject: Re: rust never sleeps
- From: T* &* M* R*
- Date: Thu, 26 Jul 2001 11:09:13 +1200
emhoffs wrote:
>
> Nine month ago, I planted a meadow. Among the grasses I planted is
> Muhlenbergia rigens. This is a tough grass that I thought would be trouble
> free, even though the soil in the meadow is heavy compacted clay with a top
> dressing of mulch. At the same time that I planted the meadow I filled
> raised beds with soil and planted more Muhlenbergia. Today the
> Muhlenbergia in the raised beds is green, long and lush while the grass in
> the unamended meadow is yellowing as it becomes covered with rust. Digging
> the meadow grasses out and replanting them in soil with better drainage is
> a lot of work that I would like to avoid. Is there a chance that the
> plants will be healthy next year if I trim off the rust and apply
> fungicide? Can I wait until the fall to do it, or is this an emergency
> situation? Don't have roses. Never had rust.
Ellen
To some extent I think you have to accept that a meadow (unlike your
garden beds) is at least appproximately a natural ecosystem and in such
systems plants just have to co-habit with some diseases, but if they are
suited to the conditions they will usually do it successfully, in much
the same way as you have to accept getting the occasional cold but
getting over it quite rapidly.
However, if you were to get the same cold following a lowering your
resistance by for instance getting very wet and chilly, or if you had
been starving for a few weeks, and then you took no special care of
yourself you might be very much weakened and possibly even die. In the
same way the grass in the maedow is obviously under harder conditions
than what you have planted in your beds and this has played a part in
getting going a severe rust attack.
If you persist with this setup, the growth of the meadow each year with
the mulch it is creating with the natural dieoff of the flowering stems
will gradually improve the clay soil and build a good humusy layer on
top. Natural grasslands such as prairies do this extremely well, so old
undisturbed prairie soils can, so I read, be as much as 15 inches deep.
You could probably speed this up if you were to apply a light dressing
of mature compost over the entire surface either in winter or early in
spring. Use only about an inch thick layer and you won't smother the
plants, but will definitely improve the vigour of the soil and increase
its food supplies, so it can feed your plants properly. The more
healthy the soil becomes the less plants will be inclined to succumb to
disease, and if they should get infected such infections are likely to
be limited and very little bother.
As to the rust-infested grass, your suggestion of cutting it down and
spraying may do some good, but I must warn you rusts are notoriously
hard to control by any sort of spraying and you should check the label
of what you use to amke sure it is suited to rust control. Make a point
of spraying the ground as well as the clumps to pick up as many spores
as possible. Killing the spores is the main thing any treatment can hope
to accomplish. I cannot suggest what you should use, as I don't know
what sprays are locally available. As an organic grower, I would be
inclined to simply use wettable sulphur, which would have the least
ecological impact and I think is as good a rust killer as many of the
fancier modern fungicides. Just a word of warning, though, do not apply
it yet if you are having very hot weather, at temps above 80F it can
cause severe burning, so your suggestion of waiting till fall is a good
one and it won't make any difference to the success of the spraying, as
you won't get rid of the rust mycelium inside the leaves anyway, only
the spores which can cause reinfection next spring.
Moira
--
Tony & Moira Ryan <theryans@xtra.co.nz>
Wainuiomata, New Zealand, SW Pacific. 12 hours ahead of Greenwich Time
