I have some beautiful purple Raven pentstemons, but all the flowers are covered with a dusty white deposit. It's definitely not mildew. What causes this, and will it go away eventually? I have some other pink penstemons and they aren't affected.
I've got this too happycottontail- just on some flowers and not on the leaves as you say - I was ignoring it but would be interested to know what it is
We shall just have to await a visit from those who are wiser and more knowledgeable than us, V S
I have a similar problem I think I recognise powdery mildew this looks like tiny bird poo, more lumpy than powdery...doesn't it sound disgusting ukk .
I have the same problem, I grew these from seed I bought in the UK. Really interested to know what it is as I too don't think it is mildew.
That's exactly what it looks like Pootler, and it definitely doesn't look like mildew. It's as though someone has come along and covered the flowers - not the leaves - with finely sifted icing sugar.
I had a quick Google but couldn't find an answer. Really want to know the answer now!
It looks almost like the farina you get on some auriculas - but I've never heard of penstemons with farina.
However, if you click on this link http://flowerona.com/page/189/ and scroll down quite a long way, you'll find a photo of a dark penstemon (not clear if it's a Raven) with the same white markings.
Perhaps it's time to make enquiries of the RHS?
Dove, my first thought was a farina of some sort, and like pootler, I googled it but without success. I looked at your link and those penstemons have it, but I think my Ravens are darker. As you say, probably time to call in the experts!
i purchased a blackberry and cream penstemon (similar dark colouring to yours) yesterday from a trusted small nursery nearby. it had some of the same white specks on it and the worker said not to worry about it as it was just what the water had done to the flowers.
I would be intrigued to find out if this is true or not!