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penstemon
Sarah262
Posts: 40
Hi
Does anyone know what could be wrong with my penstemon? It is going brown in lots of places.I thought it could be rust but the marks on the undersides of the leaves don't look orange as in books.
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Posts
Is it possible to upload a picture to help in identifying the problem?
Hi Ladybird
Thanks for the reply. The top side of the leaf has a purply brown streak and the underside is sort of dusty.
I have cut out as much of the affected stems as possible and sprayed it for rust (in case) and of course watered it. I probably should have watered more.
Do you think it will spread?
Hi Verdun
Thanks for your input. It definitely isn't over watering but maybe a little shady. It has been happily growing on the edge of a plum tree canopy for 3 or more years. I live in the south east and we have had very little rain. Maybe it is getting old? I have heard that penstemons are not long lived. It is also rather large.
Powdery mildew often appears as brown streaks once the plant tissues get infected and I suspect that might be your problem. Penstemons only live from 3-5 years and are then best replaced. They should be cut back by a half in the Autumn.
Thanks all. I will cut it back in autumn and hope for the best.
Verdun
Your post made me smile. You are right. It may not be mildew. I am thinking it is dying of thirst like a lot of plants around our area.We have drought conditions. It does get quite a lot of sun. It has been in the past, my best flowering penstemon which is why it is so big. I took cuttings last year and was worried the new plants would catch something.