Re: Acidifying soil
>
> Clarence wrote:
> :Liquid acidifiers are temporary, and you would have to be spraying every few
> :days. Use something like ferrous sulfate to increase the acidity...which
> :also increases the iron in the soil, which many soils need. Ferrous sulfate
> :works best for increasing acidity for Japanese irises which need lots of
> :acidity and lots of iron. Clarence Mahan in northern Virginia
>
> Tom Tadfor Little wrote:
> Clarence, must the ferrous sulfate be dug into the bed when it is prepared,
> or well it work as a top dressing? How often do you need to reapply it
> to maintain the pH?
Chris adds:
At the seminar I attended last weekend with John Coble of Ensata Gardens
I believe his response to a very similar question was that he used two
ways to raise the acidity in the soil;
One being the addition of agricultural sulphur (ahem, Canadian spelling
of sulfur) to the soil which caused a "slow" increase in the acidity and
lasted approx 3 years depending on the amount applied and the amount of
rainfall.
The second method being the addition of ferrous(iron)sulphate which
created a quicker remedy to re-acidify the soil.
It was my impression that Coble uses the sulphur as the long term
application amendment when preparing the beds and the ferrous sulphate
as a follow-up top dressing as required. (The Japanese iris show signs
of requiring this extra acidity by the yellowing of the foliage) The
ferrous sulphate would be lightly turned into the surrounding soil prior
to a rainfall or irrigation. Coble mentioned that he had this exact
situation at the moment cause by the fact that he has had to irrigate
heavily all this past summer which has slowly decreased the acidity from
the soil and the plantings now show signs of requiring the ferrous(iron)
sulphate treatment.
--
Christopher Hollinshead
Mississauga, Ontario Canada zone6b
AIS Region 16
Director, Canadian Iris Society
Newsletter Editor, Canadian Iris Society
e-mail: cris@netcom.ca
