Rhododendrons gone all yellow and curled - :(

megarys

Hi everyone , 
We have rhododendrons placed on east facing terrace In london planted in big metal planters in acid compost, they were good last summer and trough winter, however from around January they started looking as if they are suffering, turning yellow and leave curling (the leaves were eaten by bugs last summer) ... general observations are their soil feels moist all the time although the planters have a drainage. It gets quite windy on the terrace and sun shines up until around 11-12am. ANy ideas of whats wrong with them and how to fix it will be very much appreciated! 

Borderline

Your shrub has cold wind damage. Perhaps, think about placing it in a more sheltered part of your terrace. Evergreen shrubs can get caught by the wind, especially larger leaf shrubs.

Sadly once a shrub is under pressure, they become easy targets for all types of infestations.

Obelixx

You can help it along by giving it an instant tonic of liquid feed for ericaceous plants and, when/if it does recover and produce fresh foliage, an occasional foliar feed of 15ml of Epsom salts dissolved in 5litres of water and poured over using a spray rose on your can.

As Borderline says, they don't do well exposed to strong or cold winds or early morning sun when they've been frosted either.  Have a read of this info from the RHS to see if that helps - https://www.rhs.org.uk/advice/profile?pid=529

megarys

Thank you Borderline and Obelixx - for some reason I did not see your responses until now.... by now all of my rhododendrons are dead and so is one of the 4 camellia bushes that I have. Reading your comments and the rhs article it seems that they are the wrong plants for my situation... 

I have a terrace which faces north-east gets full blazing morning sun and on cold days horrible strong, cold and drying winds .

I also have a balcony on the opposite side of the building facing south-west which gets even stronger winds, has a roof so not much of sun apart from when it shines from the side and 3 of my remaining camellias are there. I keep the camellias close to the end of the balcony so they catch the afternoon sun bit the winds there never stop, if I move them inwards then they get less wind but they won't see any direct sun ever, so not sure if this is any good either...

I'll go and read the RHS articles for Cammelias as well but any advice on if I should keep the camellia on SW balcony or move them to the NE terrace will be very much appreciated, I am afraid they will just slowly die off if I don't come up with a plan ...
Terrace 

Balcony
 

Borderline

I'm sorry to hear about the Rhododendrons and your Camellia shrub. Apart from the exposed position, container growing for shrubs are challenging in general. Check that you are using a loam based compost like John Innes No 3 mixed with ericaceous compost. Ensure the the containers are the right size and suitable for your plant. If you also see similar nibbling going on with your other shrubs/plants you may have Vine Weevil. There's treatment for this, so look into that too.

I noticed you had a metal pot, and if not lined properly, will heat up in the summer and when the sun hits it, not ideal for Camellias and Rhododendrons. In the summer months, watering needs to be consistent. Don't be put off yet, it may be a combination of wrong container, inconsistent watering or even Vine Weevil.

Try to go for plants with small or leathery tough leaves and stiff branches. They are less likely to be damaged by harsh winds. Abelia Grandifloras are fine in that position, but may not flower that prolifically as in a southerly aspect. But good foliage all year round. Sarcococca Hookeriana var. Humilis should be fine too.