DA roses mildew performance in my garden

nikthegreek(9b/10a E of Athens)April 4, 2014

Maybe some of you will be interested in the below list which I have compiled listing the DA roses I have and classifying them with regards to powdery mildew resistance. This is no scientific observation, it is just my general impression. As you may know by now from my unrelenting moaning, PM is the main rose fungal problem in my garden in spring and fall. As always, the performance of any rose in your garden may vary.
Grading is from best to worse:
1. No affliction
2. A bit
3. Less than bad
4. Bad
5. Horrible

Here are the roses in random order (all plants are grafted):

Golden Celebration - No affliction
Jubilee Celebration - No affliction
The Prince - Horrible (I mean it, really really terrible)
Glamis Castle - Bad but tends to sort of shake it off come summer
Lady Emma Hamilton - Bad (young rose)
Jude the Oscure - Less than bad but quite a bit (young rose)
Boscobel - No affliction (young rose)
WS2000 - A bit but shakes it off come summer
Munstead Wood - No affliction
Lady of Shallot - No affliction (young rose)
Queen of Sweden - No affliction
Sharifa Asma - No affliction
Scepter'd Isle - A bit but shakes it off come summer
A Shropshire Lad - A bit but shakes it off come summer
Benjamin Britten - N/A (No signs but it's still too young to tell)
Evelyn - A bit (young rose)
Pat Austin - No affliction
The Lark Ascending - No affliction (young rose)
Abraham Darby - A bit
Teasing Georgia - A bit (young rose)
Darcey Bussel - No affliction (young rose)

Nik

This post was edited by nikthegreek on Fri, Apr 4, 14 at 5:14

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Campanula UK Z8

Do you spray a fungicide, Nik? There is one, not generally available to the public without licence (but show them your money and they don't care) - Nimrod. This is a bupirimate fungicide - non systemic - which has been truly miraculous for preventing (and curing) PM. Not cheap, but will last for years if stored carefully - any of the agrochem companies (Farmoz, Agrofarm, Fargro, Maketeshim Agaz) will stock this lifesaver (for those who need to use a fungicide).

Like me, you may well find that 'grandfather's rights (if born before 1960) preclude the requirements for spraying licenses anyway).

    Bookmark   April 4, 2014 at 6:47AM
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nikthegreek(9b/10a E of Athens)

Camps, thanks. I know lots about fungicides, both available and not available to the amateur, including withdrawn ones. Yes I have used (and I still sometimes use) bupirimate. Nimrod still has significant protective action but I'm afraid its curative effectiveness, even with elevated doses, has been compromised by overuse for a long time by greenhouse professionals. Still, it does the job as does myclobutanil (more widely available) and a couple of others (prochloraz and tebuconazole which I believe is going to be withdrawn from EU in a couple of years). I've even used triadimenol, chlorothalonil and various strobilurins. But whatever one tries one has to spray repeatedly and on schedule and rotate chemicals of different mode of action groups, something I'm not prepared to do on a regular basis anymore. I'm experimenting with potassium bicarbonate and potassium silicate to see if I can work out a reasonably effective protective protocol for the roses that are not overly prone to the fungal attack. Sulphur still works preventively if the temps are right for it (which usually they are not) but is unsightly even in the sprayable WP formulations.
Nik

PS. Nimrod, at least the concoction available over here, has a nasty smell which lingers on for 2-3 days or more and defeats one of the primary purposes of growing roses in one's garden... It may not be the active ingredient, bupirimate, itself but the solvents and additives used.

This post was edited by nikthegreek on Fri, Apr 4, 14 at 8:45

    Bookmark   April 4, 2014 at 7:17AM
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nikthegreek(9b/10a E of Athens)

It would be nice if we could turn this thread into a DA & mildew thread, so if any others want to share their experience growing DA roses in a high PM pressure area, I would like to hear from them. Let's limit this thread to DA roses to keep it manageable.
Nik

    Bookmark   April 4, 2014 at 7:40AM
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jerijen(Zone 10)

Nik -- If you can find a budded plant, you might do well with 'Prospero,' which has neither mildew nor rust here in my coastal SoCal location.

Just treat it like a China, and avoid pruning, and it will bloom like a China.

Jeri

    Bookmark   April 4, 2014 at 3:01PM
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Tessiess, SoCal Inland, 9b, 1272' elev

Thanks for bringing this up Nik, because I hadn't ever given it much thought. But now that you have, I realize that my Austins have been remarkably mildew-free, here where mildew will happily attack any susceptible roses.

Austins I grow now or have in the past, with no affliction:

The Pilgrim
Gertrude Jekyll
Happy Child
Pretty Jessica
Potter and Moore
Cottage Rose
Prospero
Wild Edric
Eglantine
Mrs. Doreen Pike
Huntington Rose
Snowdon

Melissa

    Bookmark   April 4, 2014 at 3:17PM
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prickles(Los Angeles, CA)

good thread Nik,

These are the Austins I currently grow in a no-spray, won't spray garden (the pm and/ or rust magnets already shovel-pruned):

Lady Emma Hamilton: no afflicition.

Jude the Obscure: A bit of mildew in early spring but always clears up nicely. (I think he mildews because he isn't getting enough sun. He was clean previously in a sunnier spot.)

Teasing Georgia: A bit of mildew in spring.

Young Lycidas: no afflicition.

Jubilee Celebration: no afflicition.

Wild Edric: no affliction. (A new band this year. Rugosa leaves and prickles!)

St. Cecilia: Bad. And worse: rust! (A lethal combination that isn't acceptable--she'll be getting the shovel after her spring flush.)

    Bookmark   April 4, 2014 at 3:36PM
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ingrid_vc(Z10 SoCal)

Pretty Jessica - none (but then no buds either in its third spring)
Wild Edric - none on four newly planted bands this year
Potter and Moore - slight, will probably clear up by summer
Sophy's Rose - slight on my two plants
Bishop's Castle - some, but should clear up by summer
Young Lycidas - none, bought last year
Chaucer - none, but then this plant bought last fall has hardly
any leaves yet
The Ingenious Mr. Fairchild - none

I see from my notes that at one time or another during the last eight years I had 14 other Austins that were discarded for one reason or another. Carding Mill is my only regret because that is a healthy rose which does very well in the heat and blooms a lot. Silly me, I thought it didn't fit my color scheme.....

Ingrid

    Bookmark   April 4, 2014 at 5:12PM
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Sylvia Weiser Wendel

Wonderful thread. With the caveat that these are still young roses, here's my toll at this time:
1) Queen of Sweden - not afflicted
2) Molineux - none last year, too much this year. I sprayed with Bayers Natria -- not much help. Not affecting blooms, happily.
3) Munstead Wood -- just started showing a little today. Hopefully not a big problem.
4) Carding Mill -- not afflicted
5) Alnwick Rose -- not afflicted
6) Darcey Bussell - showing a bit of a problem today for the first time.
7) Falstaff -- not afflicted, but not blooming either. The only variety that hasn't bloomed yet.
8) Tamora - not afflicted. Blooming her little head off.
Both my OGRs have mildew:
Marie Van Houtte -- ongoing problem but controllable.
Zepherine -- terrible. Horrible. May not last.
Mildew has also been a problem on my Double Delight, for what that's worth, and to a far lesser extent (but still there) on my Gold Medals.None on Granada, Mr. Lincoln, Don Juan and my various mystery roses.
Let's see what others have to say!

    Bookmark   April 4, 2014 at 11:17PM
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curdle(9b, Australia)

I have 2 Prosperos-
2nd year plant; clean - completely clean last year too
1st year plant- horrible! really horrible..but completely recovered during summer

A few others (all new this year) looked like they wanted to mildew, but never quite got around to it

Charles Rennie Mac
Cymbeline

but

Lady of Shalott
Tess of the D'urbervilles
Charles Darwin
Charlotte
Pretty Jessica

were all clean.
This years weather was strange tho.. Spring was unusually long wet and mild (didnt really get really warm until halfway through Summer)..then it just blasted everything with heat for two months, grr

    Bookmark   April 5, 2014 at 7:54AM
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tuderte(USDA 9a equiv.)

My DA roses are all quite young (most planted in May 2012, some planted May 2013) but all are completely free of any powdery mildew (so far) -

My list -

Golden Celebration
St. Swithun (climbing)
Teasing Georgia
Queen of Sweden
A Shropshire Lad (climbing)
Lichfield Angel
Wildeve

To date Spring here has been very changeable. Hot, wet, humid but also some very cold days, too. In short, the sort of weather that roses hate. After the last two days (cold and wet) we're expecting temperatures in the low to mid 20s from tomorrow. I've already noticed aphids about - haven't seen many lady bugs yet.

Tricia

    Bookmark   April 6, 2014 at 3:14AM
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tuderte(USDA 9a equiv.)

My DA roses are all quite young (most planted in May 2012, some planted May 2013) but all are completely free of any powdery mildew (so far) -

My list -

Golden Celebration
St. Swithun (climbing)
Teasing Georgia
Queen of Sweden
A Shropshire Lad (climbing)
Lichfield Angel
Wildeve

To date Spring here has been very changeable. Hot, wet, humid but also some very cold days, too. In short, the sort of weather that roses hate. After the last two days (cold and wet) we're expecting temperatures in the low to mid 20s from tomorrow. I've already noticed aphids about - haven't seen many lady bugs yet.

Tricia

    Bookmark   April 6, 2014 at 9:21AM
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daisyincrete Z10? 905feet/275 metres

Munstead Wood-some.
WS2000-some.
Abraham Darby-none
Jude the Obscure (very new)-none.
Golden Celebration- none.
Perdita-none.
Lady Emma Hamilton- none,
Teasing Georgia-none.
Pretty Jessica-none.
Young Lycidas-none.
Pat Austin-none.

Although Pat Austin and Munstead Wood are right next to each other, Pat Austin remains very clean and healthy.
Daisy

    Bookmark   April 7, 2014 at 4:05AM
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avalon2007

Very interesting thread, paying close attention to it as I have just started adding more Austins to my garden.

No rose has ever had PM in my garden (knock on wood!), so I can't really add anything specific to the discussion. Other plants do have PM here, so my roses could eventually become infected.

Somewhat off-topic question:
I couldn't help wondering if there is any connection between susceptibility to PM and tendency to develop BS? Roses that are less acclimated/less vigorous can actually die from BS here.

My very large Teasing Georgia gets a little BS but shrugs it off with no spraying of any kind. Three of the four people on this thread who mentioned TG said that it was PM-free. Just wondering if there is a general resistance to fungal diseases in some Austins.

    Bookmark   April 7, 2014 at 7:08AM
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nikthegreek(9b/10a E of Athens)

I'm curious about LEH. Most people say she has been free from PM but my specimen is mildewing a lot. Maybe I need to give her more time. Pat is one of my cleanest roses from any disease or pest, regardless of class or breeder. The problem with her is that she cannot take the strong sun so I'm growing her in a large pot in a covered veranda where she gets lots of light but only early morning sun.
Nik

This post was edited by nikthegreek on Mon, Apr 7, 14 at 7:55

    Bookmark   April 7, 2014 at 7:52AM
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