The Garden Community for Garden Lovers

Oh flipping fiddlesticks! Mildew's started on my asters!

United Kingdom Gb

I bought these dwarf asters from a garden centre last autumn. I don't know whether they are disease resistant varieties or not, but I so loved the pastel coloured flowers they produced, so I've kept them and am trying to grow them up to full size in a big pot for giving a fine display this autumn. I have some 'Myclobutanyl' systemic fungicide, but it says on the label "not suitable for asters". I am giving them good air circulation, but does anyone know of anything I can do? I have a feeling it may spread more and more. Is there anything that would be suitable to spray with?




Looks like a trip to the garden centre to find a fungicide you can use, I'm afraid. It's certainly about, my verbena bonariensis was covered in it last week.

21 May, 2009


You could try something like baking soda and water with a little vegetable oil mixed in. Or, I've also heard of using 50/50 mix of milk and water.
The idea being that you want to change the pH of the leaf surface to make it inhospitable for the fungus spores.
Personally, I've had success with the baking soda mix but I haven't ever tried it on asters.
Good luck Jonathan. :o)

22 May, 2009


Hi Gilli, Nice to hear from you. The baking soda and vegetable oil idea sounds very interesting. Presumably that might slightly alkalinify, and the oil to aid adhesion? I may well give it a go. (I'll enquire of my garden centre too Mims2) ... If it doesn't work, I could always pop my asters in the oven and see if that does the trick!

22 May, 2009


Just make sure you use baking soda (sodium bicarbonate) and not baking powder, Jonathan.....Otherwise your asters will rise nicely when you pop them in the oven but they'll still have mildew!! LOL
One tablespoon of baking soda to one gallon of water with just a bit of oil to make it stick.
I would try it on a leaf before you spray the whole plant.....just to make sure it doesn't damage the leaf.

22 May, 2009

How do I say thanks?

Answer question


Not found an answer?