CULT (OT?): Phorphorous


> 
> The next subject perhaps we could discuss, is Phosphorous as a food for
> Iris.  What are others doing in this regard?  I have noted that the
> addition of phosphorous (sp?) creates a shimmering color affect in the
> flower.  Any comments?
> 
> Nicki 

Chemically, phosphates are salts containing the element phorphorus.
Phosphorous and phosphoric are adjectives. In gardening circles,
phorphorus, phosphorous and phosphate are used interchangeably, but I
wouldn't try that around a bunch of chemists.

Unlike nitrates and potash, phosphates can be highly bound in the soil
and their inclusion in fertilizers is often taken for granted, because
the results of their use are not usually dramatic. For this reason, many
gardeners and farmers tend to ignore the phosphate level, tending only
to the immediate needs. In general, my experience has been that too much
phosphate is not a good thing. 

Phosphates are problematic in that they can build up in the soil,
especially with repeated feeding. I have seen beautiful daylily
plantings which were pushed to the max with lots of nutrients that
suddenly took a nose dive caused by accumulated phosphates. Removing
excess phosphate is not as easy as removing excess nitrogen and recovery
can take years.

Futhermore, phosphate is a dirty word when speaking of laundry
detergents these days, because of environmental concerns. If there is
more than a passing chance that the phosphate that goes on your garden
is going to end up in a stream, it may be more conscionable to forego a
dubious plant enhancement. I know we've all heard this before, but there
is nothing like soil testing to determine the real need for nutrients.
This is especially true for phosphates.

R. Dennis Hager 
Zone 7
on the bank of the Chester River, feeding into the Chesapeake Bay, the
world's largest estuary.



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