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RE: TB: Vigorous Summer Growth Question

This is a subject which I must go over thousands of times a season and being
a commercial grower have watched very carefully for a long time.  There are
a few varieties that will shed almost all their leaves. Arils and arilbreds
do it naturally as part of their method of survival, coming from arid
sections of the world.  A few tall bearded do it also but it seems to hinge
more upon a few other things rather than specific genetics.

Iris are incredibly adaptable plants.  Given poor conditions they will
survive by going into what I call survival mode....no increases, or few and
minimum growth with minimum fan size.  That plant, grown for a number of
years in those poor conditions, will stay in that mode and not grow out,
giving the appearance to all that pass that the iris "go dormant".  Take the
same rhizome from that stressed plant, long and thin, give it water and
fertilize it and it will return to its genetically determined self,
flourish, reproduce vigorously and remain green and leafy to the close of
the season.  This will take a couple years to do but the plant will make the
transition back and recover nicely.

Perception, based on visual encounters such as these, will over time
establish strong and well circulated beliefs that the plant "iris", IS going
to go dormant.  Nothing could be further from the truth.  Iris, well fed and
well watered, should flourish green and healthy until the ground cools and
the sun dips for another season.  Taken to the degree of belief and
published, Sunset magazine, put iris on the xeriscape list in the 70's.
True, it will live, and survive.....but flourish and produce 6" blossoms and
multiple increases.....No.  

I worked very closely with a member of our club here in Santa Rosa, Dean
Lindscot,(unfortunately he passed a few years ago) on an experiment in
generating rhizomes to the maximum number a plant was capable of producing
genetically.  That study, over a period of three years produced some fairly
dramatic results the first of which were published in the AIS journal a few
years ago.  Not to get far from the subject here but...growth is first a
function of genetics, then a function of nutrient, and the plant has the
capability of determining when the level nutrient and moisture is sufficient
to reproduce and bloom .  

First case is rebloomers which grow themselves crazy then bloom like there
is no tomorrow....excess growth gene...times 10 to the 50th
power....BUT...Ask all the rebloomer hybridizers...water is key to
reblooming (via growth).  Individual reaction to conditions such an water,
prior root development, rot, borers, and excess fertilizer will also give
the impression that the plant is slipping into some form of dormancy...

Bottom line...the plant depends on those nice wide leaves (battery chargers
as I like to call them) to develop the starch through the photosynthesis
process, to store in the rhizome for next years bloom.  

All that wonderful fragrance (from those that have it) is directly developed
from the starch turning to sugars and evaporating water in the spring

Those large leaves must be present and healthy to develop the remainder of
the plant for the upcoming season.  Plants left, marginally neglected or
forgotten after the bloom period, occasionally produce enough starch to
trigger bloom but again it would be those hybrids with a low starch level
gene trigger.

Unfortunately, many people become dissatisfied with the plant when it stops
blooming for them or "goes dormant".  I've taken it on as a crusade in our
area to bring them back into the "Iris Lovers Fold" if you will.

New growth, rhizome replication and blooming are directly proportional to
the application of appropriate water and fertilizer.  

Impatient need not apply

Ross...My Wild Iris Rows

-----Original Message-----
From: owner-iris@hort.net [mailto:owner-iris@hort.net] On Behalf Of
Williams, Michael
Sent: Sunday, July 23, 2006 10:08 AM
To: iris@hort.net
Subject: [iris] TB: Vigorous Summer Growth Question

I have been under the impression that iris plants are dormant during the
summer months. However, I have two first year plants here that have pushed
three and five new fans just in the last month when it has been the hottest
period of the year. These fans are healthy and around 3 to 5 inches in
at this point. Temps here have averaged high 80s with heat indices in the
to mid 90s. We have had a couple of days where the heat index exceeded 100.
Would such growth as this be unique to these varieties? All of the other
irises do definitely seem dormant. Have others of you experienced this? I am
simply curious.

Mike in Zone 8 (Coastal SC)
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