Scottish Rock Garden Club Forum

Specific Families and Genera => Rhododendron and other Ericaceae => Topic started by: glynnffc on November 27, 2013, 01:00:19 PM

Title: Every garden should have one..but not like this Help
Post by: glynnffc on November 27, 2013, 01:00:19 PM

My Rh.bureavii is not well. All summer it has been curling leaves and it is now getting a lot worse.I have just lopped three branches where most if not all of the leaves were badly curled and wilted.
The plant sits under a tulip tree,but here in the north lakes lack of water is not a problem.
Most sites seem to suggest drought ,but this must be something else.The undersides  of the leaves look normal,no insects, nothing.
Any suggestions?
[attach=1]
Glynn

Title: Re: Every garden should have one..but not like this Help
Post by: johnw on November 27, 2013, 04:02:50 PM

Glynn - Looks like Phytophthora to me.  Make sure you dip you pruners in bleach when making each cut.

Phytophthora cactorum - branch die-back. Prune out affected parts and move to another location with better drainage. Poor drainage is the usual cause.   My thought is the problem is preceded by extremely wet weather with poor drainage involved and/or heat or a long period of drought casuing root damage which lead to Phytophthora infection.  Can sometimes be salvaged.

Phytophthora cinnamoni - wilting when soil is moist, can start with a branch but within weeks the whole plant collapses.  "My thought" above applies.  Lucjk of the draw which variety you get but would appear you have the former.

R. bureavii is in  the Taliensia and these want especially sharpo drainage.  Se Bent Erneberg's picture of R. roxieanum  - another Taliensia - seedlings in the wild and take heed. https://picasaweb.google.com/102102020346806227405/ChinaSBBE2013FlowersAndMountains?authkey=Gv1sRgCKqUyLqxiYi_DA#5944343113145490546 (https://picasaweb.google.com/102102020346806227405/ChinaSBBE2013FlowersAndMountains?authkey=Gv1sRgCKqUyLqxiYi_DA#5944343113145490546)

johnw    - +11c and going to +15c, rain up to 80mm total, west & north of NS will be a winter wonderland. 

Title: Re: Every garden should have one..but not like this Help
Post by: Diane Whitehead on November 27, 2013, 05:40:31 PM

Poor drainage is not exactly what it sounds like - the plants aren't
sitting in a puddle - as long as there is water flowing,
the  zoospores are disseminated and infect feeder roots.  This year I
lost a grevillea growing on a sandy bank, and I have read of avocado
orchards in Australia and also, I think, Israel, where there were heavy
losses due to a rainstorm where there was water in the soil for just
a few hours.

Title: Re: Every garden should have one..but not like this Help
Post by: glynnffc on November 27, 2013, 08:45:58 PM

Thanks for the help,I will certainly sterilise my secateurs now i know its fungal.
I shall move the plant asap and hope for the best.