Other things that cause spotting...

David,

One of our friends from a nearby farm paid us a visit today. He brought with him a product called Ridomil Gold. It's a systemic fungicide to aggresively kill downy mildew. Apparently they use a lot of it because they get a lot of downy mildew in their poppies... and guess what I have growing in the paddock next to my rose gardens...

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No prizes for guessing where my DM problem is coming from. As my friend was driving down the driveway he said he could see the DM all through my neighbour's poppies. Photo was taken this afternoon, about a half hour ago.

Ridomil Gold is good, "but" I think it has 2 chemicals in it, one being not real bee friendly. I hope it is not Gold. There are 2 types of ridomil.

It's Ridomil Gold MZ WG. It looks to have two active ingredients; mancozeb (which is a sulphur based product that is a preventative for blackspot in rose fungicides), and Metalaxyl-M... not one I'm familiar with. The bees don't seem to be affected much in next door's poppy fields shown above. We have millions of them around atm. According to the material safety data sheet ( see: [You must be registered and logged in to see this link.] ) it is non-toxic to bees. Macozeb has been shown to be toxic (LD50) to bees after 48 hours of continuous exposure (see: [You must be registered and logged in to see this link.] )

Simon, that link is in Chinese I think lol. I have sprayed all my roses with Mancozeb Plus. It details Downy Mildew on the label. I sprayed after the bees had gone to bed. I have also got Fongarid which will be my next application, but after Christmas. Can you spray with Fongarid or is it just a soil treatment?

I put the Fongarid all over.. I don't usually spray anything though, Val, and won't be after I get this under control either... I just don't want to lose my roses to this.

It is important to emphasise that no matter which kind of rose you are into, very few roses have any natural resistance to downy mildew. Only the rugosa here are showing no signs at all. My seedlings are especially vulnerable as their resistance is not yet at full strength. Some of the worst affected are the Teas and the Chinas but this is, IMO, just a reflection of trying to grow them in Tasmania on the edge of their climatic tolerances... though Cass Bernstein, in California, mentioned the other day that she also finds them particularly susceptible too. This is not a slight on them because in warm areas where this disease is not an issue they clearly out perform everything... they have no need to develop resistance againts DM so why would they?

It doesn't usually kill the adult roses and every year I get a bit of it that I can live with. This year is such a bad year for it (and everything else... botrytis is running through causing havoc here too), and it stays in the tissue from one season to the next so I need to do something about it or risk losing things I have worked hard to acquire, cultivate, and breed from. A serious case of downy mildew weakens the plant to the point where it can no longer even make foliage and without foliage it will die. The spores can live for up to a month on the dead leaves so I removed the dead foliage from the ones in the pots (because they are under more stress than roses in the garden anyway) and in the garden I've cut back the worst affected roses to force them to to make new leaves and will put the Ridomil Gold/Mancozeb on them when they start to re-sprout. The Fongarid was put onto all my potted roses/seedlings last week as a soil drench but I also sprayed it on the foliage.

None of the curative treatments that the various agronomists have recommended to me work for longer than 14 days... I am hoping it gets real hot soon so I don't get locked into a 14 day spray cycle... will pack up and get rid of all my roses if I have to do that!

I think Rosalie's point about adding sulphate of ammonia to thicken cell walls is a good one as well... I haven't done that for a few years because I don't add anything except mulch/manure but I think it's something I should try and get back into the habit of doing.

So... I hate this so much... but don't see any other way around it at this point.

In my garden, it's (some) HPs, DPs and HTs that have got it; the Teas and Chinas are OK. We've got as couple of 34C's brewing, and I don't expect to lose any plants from it.

I know Simon, it is even harder for you because you are breeding them too. If I lose a couple that's no big deal, they are easily replaced, but you have spent so much time and thought into your seedlings. A bout of really hot days would fix a lot of it up.
I have strawberries with mildew too, and I'm watching the tomatoes carefully.

Simon, how are your sick roses going? Mine are still producing infected leaves but not in the amount that they were doing previously.

In the process of getting cleaned up... is a big job that will happen over the next week or so. Resprouting is taking place... I'm trying to keep up with the watering atm... either famine or flood around here and the top soil dries out so quickly. We've had our first dry week in who knows how many weeks and it looks like it hasn't rained for a year.

We have had less rain over the last week or so.I'm just trimming mine for the second time. We've got hot weather forecast for next weekend so that will help. I've got regrowth happening too. I was so looking forward to showing my rose garden to some family who are coming over from the UK in Feb. Oh well they'll have to come again next year won't they? LOL

Simon - any improvement in your roses?
I spent SO much money on Fongarid, and you can't buy it in more economic quantities.
I'm still cleaning up and hoping that some of the sticks that were rose bushes will throw up a shoot or two. Some of them have already done this, but I suspect that a few were too badly affected.

A lot are showing improvements... like yours, some of mine will I think meet their maker soon.

I'll keep my fingers crossed for you Simon.

You know what I did Val... I decided I was only going to spray my seedlings and nothing else. At the end of the season it will be the last man standing and the others will be ditched... some roses, it seems, show pretty good natural reistsance so these are the ones I want to stay on. It is really hard to watch the others but in the end I think it is for the best.

I understand what you mean. It's a hard way to be selective though. I admire your attitude and I hope it really is for the best for you.
I feel so disappointed, my main reason for growing roses was that they are so tough and survive drought etc. It's hard to know what to replace them with, you can't plant new roses where they have died.

why not?

Well, it might be an old wives tale I guess, but I've heard that it is so.

I take it with a grain of salt (and a sip of lemon and a shot of tequila ) myself. I always do it and have never seen a problem since I started growing roses 30ish years ago.

I'll drink to that then! LOL
Well it is a furphy then.
I might be in the market for more roses next season then

Finally the last of the Downy Mildew is gone. Most of the roses have put out lots of new shoots. Some of them are in bloom, and although the amount of blooms is a lot less than usual, what there are are beautiful.. I've lost 2 plants and a third is on its way out, so that's not too bad.
Simon I hope yours are all OK.

Val, what are the 2 you lost and third possible loss. I "think" if you cut them right back close to the bud union/graft and keep them moist they "might" return if you have patience.

Simon, I have lost Princesse de Monaco and Winchester Cathedral. WC did shoot a couple of new bits but dieback killed the little cane. Blackberry Nip, French Lace and Chartreuse de Parme look pretty weak.

My name is not Simon, but he can help, at your lesuire can I/Simon have a picture please or do we have to come back to your house and help

Val... the God's are smiling on me... I'm not going to lose a single rose. Winchester Cathedral actually came through relatively untouched. Roses like Double Delight, Just Joey, and Lavender Pinnochio looked like they would but they haven't. I sprayed nothing in the garden. The only thing I did spray was my seedlings and they are really taking off. Everything else was just cut back hard, dead foliage removed, watered in well with the flood rains we had and mulched. Even Red Intuition refuses to die... I might have to help it along a bit

Sorry David! What do you want a picture of???

Simon, I'm so pleased your roses survived!! Yes all that rain must have helped their recovery. I'm going to cut back the ones I mentioned even more I think. (Not the dead one!)