Grey mould

Well, as some of you are aware, it's been a miserable two weeks in Melbourne, and at my place it the hills it's been raining or drizzling constantly every day until yesterday.

I've been in bed with the flu all week (typical!) but I'm starting to feel alive again today, and the sun is shining, so I ventured out to look at my roses. They are seriously covered in a furry grey mould.

It's not PM, this is something else much worse, and it's insane! It's on buds, mature flowers and spent flowers, especially those close to the ground (a lot of the canes have been bent down by either the wind or from the weight of being wet for two weeks). And it's not discriminating either - it's on my teas, bourbons, and Austin's.

I'm just waiting for the pics to upload, then I'll show you all. I've never seen this on any plant before.

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Here is the dreaded mould on Souv de la Malmaison (top) and Marie van Houtte (bottom).

So I'm just going to cut off the mouldy bits and bin them, then cut all remaining flowers for the vase.

How close are you to a vineyard/orchard Zoe, have a look at these links,

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my other suggestion would be to try and smother all with a oil of your choice, not nice to see this.

Yeah, it's pretty ugly! There are some vineyards in the Yarra Valley, about 45 mins from here, but I don't know anyone who works there so getting hold of fungicides would be tricky. And you know me David, I'm not really into spraying chemicals

I wonder if a copper based spray might help? Like the stuff the organic folks use on peaches and cherries in winter... I will do some investigating.

So it seems that most of the anti-fungal sprays available to the general public at Bunnings have potassium bicarbonate as the active ingredient. Which is just potash, I think?

I know potash used to be made from wood ashes, so I'm thinking I might try to scrounge some wood ash from the neighbourhood fireplaces and use it somehow on the roses... Thinking, thinking...

Using potassium bicarbonate as a spray on roses for black spot & mildew, needs to have the recommended amount of vegetable oil for a better success rate.

Oh right, thanks Paul.bthat makes things a bit trickier.

muscovyduckling wrote:Oh right, thanks Paul.bthat makes things a bit trickier.

your welcome lol

paulh wrote:Using potassium bicarbonate as a spray on roses for black spot & mildew, needs to have the recommended amount of vegetable oil for a better success rate.

do you know how to make up the correct ratio, Paul?

You are not on your own muscovy with your roses. Here thousands of miles away from you some of my roses are showing the same symptoms.. The wheather is playing havocs. It is unbelieveable that everything is developing ready to flower and flowering at the same time like almost two monhts early, some roses covered with mould and the worst my belowed dwarf red leaved Nectarine fruit tree is suffering from curled leaves effect because of the wet and hot humid weather... So many flowers and fruits are so early even the the curry plant gooseberries and raspberries will be ready to pick up within three weeks. One minute it is pipin hot and humid pouring with rain and the next it is downt to almost below zero celcius...

Here I am suspecting that it is El Nino effect. Do you have a current system similar to El Nino in the ocean near you?

Ratio would be awesome if you have it paul!

Alya, I'm sorry that you're experiencing it too  we did have a very humid summer here and fruit growers up in the hills experienced brown rot in their plums for the first time in 25 years. There were some El Niño warnings for this coming year, but in Australia we usually find that El Niño weather patterns cause very hot dry summers for us with increased risk of bush fires. I have not really thought about how El Niño affects us during the autumns and winters because we're all just so worried about how it will affect us in summer!

Use 30 grams of potassium bicarbonate in 9-10 litres of water,then add 20mls of vegetable oil, mixing well

I have this on a couple of my HTs. Not happy Jan! (or Zoe!!). Thanks Paul. Will also use this. I'm not very far from Zoe (muscovy), and can't think where this has come from either. Could it be wind carrying it? Don't laugh!!

Thanks Paul  

I don't know either Sue. It's odd.

Over Winter and drift can be the problem Zoe