By Nariz
Spain 
Can anybody help with whatever's causing my Rhododendron to be sick-looking? I pruned it back severely in mid-June after flowering and pruned out the leaves that were already showing this brown-ness, but the unaffected leaves, apart from the new shoots. are now affected with whatever-it-is. Heeeeeeeelp!
3 Jul, 2012
Answers
How long have you had the rhododendron and is it growing in acidic, ericaceous soil? Rhododendrons need a lot of water does it get sufficient?
3 Jul, 2012
Thanks Ojib and MG, this is its fourth year, it's growing in ericaceous soil, is fed with ericaceous feed regularly, is watered daily (at least a gallon and more if it rains) and is in a position that gets morning sun, but shade from mid-day onwards. The leaf problem has only occurred this year.
3 Jul, 2012
I'm at a loss - have you done anything different this year?
3 Jul, 2012
Phytophthora ???
3 Jul, 2012
Done nothing different, except the hard prune MG, and the leaf-browning was already happening then.
Um ... sorry Pim, but what's Phytophthora? I've not come across any diseases on my plants during my short years of gardening interest and I know zilch about chemistry.
4 Jul, 2012
Sorry Nariz no idea try sending a pm to Bamboo and asking her to take a look at the question.
4 Jul, 2012
It hopefully wont be Phytophthora Nariz I lost my Rhododendron last year. It died very quickly the local park gardener said it was probably Phytophthora
http://www.forestry.gov.uk/pramorum
4 Jul, 2012
Interesting Pimpernel I too hope it isn't the cause
4 Jul, 2012
Could it be sun scorch? They seem to do best where it is cool and shady. Others here will help more, I'm sure.
3 Jul, 2012