Well,
A little bit of web research, a bit of home chemistry and I have a vase of
roses that used to be Red and are now Purple(ish).
(Posted without pictures - Server problem)
The main colour agent in red roses is a series of pigments (Anthocyanins )
that are quite sensitive to PH.
A common high school science experiment is to extract the pigment from red
roses using alcohol,
and use it to test PH - acid is red, alkaline is blue.
Make the vase water a bit alkaline and the red roses start to change colour
to purple - it takes 12 - 18 hrs.
I used sodium bicarbonate in my test. Differnet checmical s may have
different results.
Presumably, a plant in alkaline soil (PH 7) would have the same effect,
potentially more so as it would affect the bud during growth.
(Sorry, but I'm not about to lime my roses to check!)
Different roses have different pigment combinations and different internal
PH in the petals - therefore different sensitivity.
(One site indicated that Yellows may be more stable)
So my advice would be to check the soil PH and let us know the result..
Regards,
Douglas.
Sites / citations listed below.
================================================
http://www.bmi.net/roseguy/redshoot.html
Colors in plants come from three major structures: chlorophyll (for the
green); carotenoids (for the yellows and oranges); and anthocyanins (for the
rest, especially reds, purples, blues).
There are several types of anthocyanins, slightly different chemically, and
their combinations in the plant are responsible for why a plant's flower is
red, yellow, blue, etc
================================================== ===================
http://www.bmi.net/roseguy/scph.html
An out-of-balance soil pH will interfere with the plant's uptake of various
nutrients from the soil.
In acidic soils (pH lower than 7), nitrogen, potassium, calcium, phosphorous
and magnesium will become less available,
and completely unavailable at a pH of 4. In extremely acidic soils,
aluminum, manganese and iron can become toxic to the plant.
In alkaline soils (pH above 7), phosphorous, iron, copper, zinc, boron and
manganese will become less available.
Extremely alkalinity will release toxic amounts of molybdenum.
================================================== ====
http://www.carolina.com/manuals/manu...%20Flowers.pdf
Anthocyanins are a group of pigments that generate pink, red, purple, and
blue colors in flowers and fruits. The term anthocyanin derives from the
Greek words for plant and blue. The more common anthocyanins generate
orange-red, purple-red, bluish-purple, rosy-red, and a host of purple hues.
Each pigment does not produce a set color; rather, colors range widely in
appearance, depending on other conditions of the plant cell where the
pigment is dissolved. Many of these compounds are pH sensitive.
================================================== ==============
http://www.uni-regensburg.de/Fakulta...p26_anth-e.htm
"Douglas@Canberra_Australia" wrote
in message ...
You haven't mentioned whether these are new roses that are flowering for
the
first time, or whether they are old favourites.
Assuming from your note that they are new, possible bare rooted - there
are
a couple of other factors that may come to bear:
1) I have a striking pale pink / cream rose in my bed of newly
planted reds;
I suspect it was mis-tagged by the grower, I ordered a "Spirit
of Hope";
I think I got a "Spirit of Peace" even though it was tagged
"Spirit of Hope".
If the roses are new, you may want to talk to the supplier and
see if they have had similar problems reported.
(and how reputable the supplier is?)
2) Did you buy from a catalogue? The real colours are often quite
differnet from the pictures on the Web / Catalogue.
3) When I was investigating roses, I went to a number of Rose
gardens, and the same rose on different root-stocks / soils types
from different suppliers in different climates can be quite
different in colour, scent and bloom form.
When I was picking roses, I was lucky enough to visit 4 cities, spanning a
distance equivalent to the distance across the USA east to west; and
probably 4 of your climate zones.
Otherwise, I have noticed a significant variation of rose colouration can
occur (especially on new bare roots during their first year)
by any number of factors; Heat being the most obvious; but PH, fertilizer,
wateriing regime, soil type all seem to affect colour.
I have a groundcover (unknown) that will go from Deep red to Palest pink
in
the course of a day purely on heat/moisture stress.
I have had quite a bit of variation throughout this summer (We are just
coming into autumn here) in all of the bare rooted roses I planted this
year.
We started off with a very wet season, and then it finished up quite dry.
I
also noticed a change in flower color / form when I switched fertilizer
types.
If these are new roses, I would be reluctant to "shovel prune" until the
plants had a year to settle in, and for you to rule out other factors.
While I haven't had a chance to test the hypothesis, I suspect roses are a
bit more sensitive (colouration) to soil PH than generally advertised.
The original PH testing chemicals were pigments drawn from plants, and
hydrangas are an extreme example changing from Pink to Blue depending on
soil PH.
No quick answer I am afraid, looks like you need to do a bit more
detective
work.
Douglas;
Australia.
wrote in message
oups.com...
Hi all!
Well, my roses are in bloom--yay!!!! But there is something very
odd...
You see, I have fifteen rosebushes so far... 10 red and 5 yellow. In
the red row, there a 3 Mister Lincolns, 3 Oklahomas, 2 Climbing
Blaze, a Monumental, and a Climbing Don Juan. The yellow row consists
of: 1 Electra, 1 Golden Celebration, 1 Julia Child, 1 Canary Diamond,
and 1 Gold Glow.
All of the bushes have buds. A few are in full bloom. All of my
yellow roses are coming out the right colors.... several beautiful
shades of yellow. The problem--although they are absolutely stunning
and beautiful--is with the red row. The blooms are nowhere near the
color they are supposed to be. The Mister Lincolns that have bloomed
so far have produced large, heavily scented flowers that are beautiful,
but instead of being a deep rich red, they are instead a vibrant and
rich but decidedly PURPLE color. Likewise with the Oklahomas, although
they are an even lighter shade of purple. The Monumental and Don Juan
have not opened yet, so I don't know what color they will be. The
Climbing Blaze are blooming as well. Their color isn't purple like the
others, but it isn't exactly red like it should be, either. Instead,
they are a bright orange!
So, the question is: Why? Is it perhaps the soil content, or the
fertilizer I used? A combination of both? And if that is the case,
why are the yellows coming in properly? My home is on a mobile home
lot one street away from the river and has several different types of
soil--probably due to the preparation for putting a trailer on the lot.
At one end of the trailer, where the Climbing Blaze and Don Juan are
located, it is all red clay? Towards the middle of the house, where
the bulk of the roses are planted, the soil is a mixture of red and
brown clay. At the back of the house, the soil is mostly chert. I
fertilize the plants with the Wal-Mart equivalent of Miracle Gro for
Roses.
Any ideas?
Thanks!
Jason
(A Satisfied but Mystified Rose-Gardener)
Zone 7b.