Rhododendron looking very poorly - what do to?

Hi
Over 20 years ago I was given a Rhododendron in a pot which did quite well in the pot, flowering really consistently but was ultimately only growing to about 5 feet tall due to the limitations of being in a pot. A couple of years ago our gardener transplanted it from the pot, including the soil in the pot and for the first few years it did OK in the garden but the last few years it's looked extremely poorly indeed. It doesn't get much direct sun but is in a similar place in the garden to the pot where it did OK. It's on the north side of a fence. It would be a pity to lose the plant completely as it's got sentimental value. Based in Edinburgh. Pictures taken a week ago.

thanks Craig

 

I think you may have a vine weevil problem, possibly its drying out in summer and maybe your soil isn't acidic enough.
It doesn't look good and touch and go if its worth keeping.

 

Hi, welcome to GC It's under attack from vine weevils. They're notoriously difficult to get rid of in the soil. I'd re-pot it in ericaceous compost (the rootball probably hasn't grown much) and drench it with whatever is available over there to kill off the larvae. Or you could wait until the weather warms up and use nematodes, but give it a high-nitrogen ericaceous feed meanwhile. Either dig over the spot where it's planted and remove any larvae you find or drench the soil too. Then re-plant something resistant to the little so-and-so's!

 

I'd say the damage was done a long time ago. It often takes a while to show up, as with many shrubs. If it was long term potted and didn't have adequate care, it would have been almost impossible to rejuvenate it easily. If it was root bound when planted out, it won't have recovered well, regardless of the conditions. They're tough plants, but that looks beyond help.
Vine weevil yes, but a healthy shrub would shrug that off and it would then just be aesthetic damage. Looking at that, the weevil damage might be too bad now for recovery. You'd have to dig it up to see.
The soil and surrounding area looks very bad too. They really don't need particularly acidic soil. What they do need is decent, healthy soil that has had plenty of organic matter added, and mulched to prevent moisture loss as they're shallow rooting. Bark is ideal for that. Good drainage as well - they like loadsof rain, but they don't like being waterlogged. Some will tolerate a little alkalinity, but the majority are happy on neutral as long as it isn't too alkaline.
You're on the drier side of the country up here, but it's still plenty moist enough.
Sorry, but I doubt that will ever look decent. You could try cutting it back after it's flowered, and seriously improving it's soil conditions, but I think the damage is beyond repair.

 

As you live in Edinburgh you are 99.9% likely to have acidic soil so that is at least a bonus. If you really want to try and save the Rhododendron then you need to lift it, this is pretty easy as Rhododendrons are surface rooters and yours looks pretty small still.There is a saying that if you can physically move them they will survive the move. I have moved huge ones with 4 people and the sheet under the plant method, hard work but worth it,
Once you have lifted your plant tease out the roots which are probably constricted having been in a pot for years unless that was done prior to planting in the garden. Then wash off all the soil to get rid of as many of the Vine weevils plus their eggs as possible. Professional Rhododendron sellers do this to adhere to export requirements.
Once you have cleaned the plant then either replant in a different spot but improve your soil considerably or plant it is a big tub. Ideally add peat….oh you can’t do that nowadays despite the Irish burning tonnes of the stuff still. Relatives in Ireland still heat their homes with peat so it makes a bit of a mockery re there being a ban in it’s use in horticulture….well I presume there is a ban but stand corrected if mistaken.
Ok so no peat, the best alternative is leaf mould but that is very difficult to come by unless you make your own as I do. Your best bet would be to buy a large bag of Ericaceous compost and use all of it to plant the shrub into. You can also prune it to improve the shape.
This is quite a lot of work but if the plant has sentimental value them maybe it is worth a try. Unfortunately if you decide to buy a replacement that too will get attacked or worse you will buy a Rhododendron that already harbours Vine Weevil. I bought a very expensive Rhododendron from the most “ famous” Rhododendron and Azalea growers in Scotland ( in Perthshire) and I found Vine Weevils in the pot.

 

I managed to import vine weevil on a small plant I got from a very reliable source. Such is life.
You can certainly wash off the soil and leave the grubs out for birds. I've done that several times - Heucheras [in pots] are a big favourite.
I think the rhodo in question is far from small - the OP did say it had got to 5 feet in the pot, it has a fair amount of woody growth, but that's the problem - there's not much else on it, judging from the pix. I doubt the root system has spread or done much in the time it's been in the ground.
That's why I also suggested lifting it to check the root system, but it may not be easy. If it was a small plant, it's very easy. Not so easy with one that size without some help.
The other option is to try layering a stem or two, but it's hard to see from the pix if there's anything viable. Always difficult when it has sentimental value though.

 

Maybe the Rhododendron is bigger than it looks in the photo but even so at 5 ft that is not what I personally would call large and the person has a gardener to help. It all depends on just how sentimental the person feels about the plant. If it were me I would give up on it. Agree layering would be an option but there would appear no suitable branches close enough to the ground to achieve this. Perhaps if siliconglen knows the variety of Rhododendron they could get a replacement of the same type.

 

I'd agree - I wouldn't waste time trying to save that, but some people are very sentimental about plants.
I'm not
You can sometimes layer by attaching a container, but I doubt that's viable either. Hard to tell from those photos though.

 

Take the flower bud off, cut back all dead wood to living wood, clear all competing plants or weeds from the area.

Leave it for now and watch it closely for new growth, if it wants to survive it will, will it look good, probably not for a few years.