Re: Re: CULT:REB: mulch
In a message dated 12/23/2002 3:10:48 PM Central Standard Time,
lmann@volfirst.net writes:
> Bill - I'm not disagreeing with the 'blooms when mature enough' concept,
> only saying that rebloomers don't start to bloom here until soil
> temperatures cool off a bit from summer highs. I have watered enough to
> keep them growing, but they just won't budge till it cools a bit.
>
> Several years ago, there were some posts about night respiration rates
> of ?MDBs?
Under the scenario which I speculated earlier, the most obvious difference is
the mean soil temperature in the two different halves of the year and the
cyclical changes in that mean temperature, particularly near the surface. In
those areas where we see the consistent, reliable rebloom in a wide range of
irises, I suspect they have at least one thing going on that we do not, wider
fluctuation in average daily temps over a longer period of time at a mean
temperature conducive to continued growth. Don't know, just speculating. But
too, suspect the fluctuation within a given temp range promoting growth aids
in stalk initiation when light levels reach the proper level. I further
suspect that growth must be more or less continuous (effects of suberization
on bloom might be viewed as an extreme change in growth cycle) during the
time the juvenile rhizome is maturing. Might be fairly easily tested by
potting a few rebloomers that are reluctant here and refrigerating them
during a portion of night.
C. Campi posted a pic of Grape Reprise (Moores 1994) performing admirably in
California Rebloom Lah Lah Land. Registered as Sept. rebloom in Mississippi,
Grape Reprise did not make the Old South narrow band report last year. I've
not collected the data this year so do not know. But, my point if there is
one, is that rebloom capacity is not particularly challenged when grown under
conditions conducive to allowing it to happen. Garden earth acts as a heat
sink and ultimately reaches a thermodynamic balance known as steady state
except at points very near the surface. If my supposition is correct, when
there is relatively narrow fluctuation in temperature a mulch would have the
effect of lowering the steady state temperature but would promote rebloom
only to the degree lowering the steady state temperature aids in maintaining
the soil temperature at levels that promote continuing growth of the plant.
Thinkin' hurts my head. For MDB's I must bend over to pollinate and that
hurts my back. Now I dun started ah wonderin' if the reason for reports of
higher percentages of pollen strikes on apical blooms in TB's is
statistically related to the age of the pollinaters reportin'. <g>
Bill Burleson
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