Re: adaptability/microhabitat

I have been under the impression that bearded iris, especially TB's, have a
very high Ca requirement.  The soil I had in Idaho was closely related to some
that were known to have about 39,000 lbs. per acre of lime in the 8-inch root
zone.  That is an enormous amount of lime!  Peaches, plums, iris, tulips and
lilacs loved those conditions.  To grow Rhododendrons under these conditions
took years of soil preparation, creation of an acid-inducing microclimate that
avoided the extremes of insolation, temperature and rates of temperature
change.  Ferns and Rhododendrons were restricted to the north sides of houses
located in the areas with the most mature irrigated soils, to say the least.

Here in Tennessee or North Carolina the exact opposite conditions apply.  The
soils already *are* the extreme of mature, old, acid-forming natural
conditions and have very little natural Calcium except for occasional layers
of marble, not exactly known to be a readily available source of the nutrient.
Consequently, Barry Blyth's wise counsel applies especially to us.  As I
recall when you first related Barry's reply to your question, Linda, you
mentioned a semi-annual feeding applied like snow.

Bill Burleson, on the SpaceAgeRobin, republished some data he found on lbs.
per acre (or per hundred square feet, I forget which) required to alter the pH
of a soil by a specific degree.  I believe it was stated in terms of
soils with specific acid pH being  converted to a neutral condition.  The
amounts of lime required were astonishingly large.

The roles that Ca plays in plant physiology are crucial, one in particular
being the passage of specific ions through cell walls.  It has been mentioned
before on Iris-talk that ample applications of lime on bearded iris seems also
to have a beneficial reduction of losses to soft rot, possibly due to the role
played by Ca ions mentioned above.

Irises of the lime-loving if not lime-requiring, not just lime-tolerant,
bearded iris type *will* grow in our acid soils without amendment, it is true,
but when I compare the quality of growth I took for granted in the
Intermountain West with what I see here, I can hardly believe how poorly
bearded iris grow in western NC.

I feel almost like I am being forced to choose--to fight the natural habitat
and work constantly to create the conditions needed for quality bearded iris
growth--or throw in the towel, so to speak, and go with what *does* thrive
under our conditions--*Iris verna,* *cristata,* and other Evansias, Siberians,
and with ample water seasonally applied, the LA's and JI's.  There are those
here who have done just that.  That's not the direction I want to go.  I enjoy
growing these types, and appreciate the ease of their care here, but bearded
irises, especially TB's, are my first love and have been since I was five
years old.

Despite borers, energetic moles, the labor of heavy lime and gypsum
applications, spring freezes and winter vagaries of temperature and humidity I
persist.  I must admit I do understand Linda Mann's "slough of despond," but I
refuse to surrender.  I doubt the solution lies in genetic adaptation.  I
think it to lie simply in our response to the need to create cultural
conditions favorable to our TB's.

Neil Mogensen  z 7 in western NC

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