saki wrote:

(Shiva) wrote in
news:43f260d08ead66e6bfc89a8024e4d344@TeraNews:


If I read the original poster's article correctly (and I apologize if
I've missed something) there was no overt mention of blossoms that "rot
on the stem", and the photo doesn't entirely illustrate this scenario.

In truth, the original poster's language in the post was rather ambiguous.
Here is what he said:

"My rose plants have not been producing good roses this year. It looks
like they are brownish on the outside."

Does this mean on the outside of the stems, blooms, or both? The photo
showed only brown on the bloom, to my eye. Exactly how botrytis starts on
my roses.

"Before they bloom, while they bloom, they look 20% dead."

Again, I took this to mean that the blooms look dead, not the stems. But
apparently botyrtis can cause both? My orthenex nips it in the bud, so I
have no idea what an advanced case looks like.

"One store sold me generic disease control, one store said it looks fine,
and another store said although he couldn't find any thrips, it had all the
symptoms."

I have seen exactly two things cause the sort of browning on blossoms
that "Me"'s roses showed in the photo he posted: thrips and botrytis.
NEVER "water damage." In my garden where everything, but EVERYTHING gets
lots of overhead watering plus plenty of storms and lots of high and low
temps.

I have a picture of one of the roses at
http://home.earthlink.net/~cenews/garden/

He/she said "they are brownish on the outside" and look "20% dead",
which I take to mean that the damage is partial. The photo seems to
illustrate this.

Yes, it is on the blooms.

There are several reasons why this may have occurred. One, as has been
mentioned, is botrytis (which, full-blown, isn't very pretty at all, and
absolutely requires spraying with fungicide); another is thrips.

Thrips are easy to see. I can see them crawling on the bloom without even
shaking them over paper. I do not have perfect vision, either. "Me" said he
had someone at a "store" look for thrips, and that he found none.

Two other situations to consider are excessive heat (especially when
coupled with drought, if present) and water/rain damage.

It does get hot here. For example, it was in the 90s yesterday. In July
and August it will stay there, and reach the 100s on occasion.



While most roses, as you point out, like a bit of a spray-off with the
hose (which also helps control pests and diseases), a prolonged rain
during the critical blossom-forming period will, for a few select
varieties (usually light-colored ones), result in brownish patches on
unopened blossoms

I take your word for this, though I have never seen it.

or outright "balling", where the blossom refuses to
open and sits tempestuously on the stem until it dries out.

Two of my roses did this: the ugly Peace and the uglier Amelia Earhart--
two roses with many petals. They did not have time to rot since I cut them
off.


We've had more than our normal share of rain this
spring in Southern California (I noted that the poster who asked about
this problem is also located here), in particular a full-day rainstorm a
couple or three weekends ago.

Your best point yet! There may indeed be conditions in N. California and
elsewhere I have never seen. While it is hard to fathom that water on rose
petals may be different there, I must concede that I really do not know.



Whatever the poster decides, I'd like to chime in with my appreciation
for the foliage!

Me too. Absolutely magnificent. The rose itself must have naturally dark
green foliage, my very favorite.

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