Rhododendron

I have a couple of Rhododendron's, one (in a pot) I have had for a while and having not really known how to look after it, I now find myself with something that has all the foliage in the top 25% of the plant, like I have let it grow too big ?. The other (in the ground) I got early this year and really want to keep it fairly compact i.e not let it grow out of control (like the other one). So I guess my question is how/when/can I, prune it ? I know the new buds start pretty much straight away, once the old flowers have gone, so if I understand it right, if I pruned now I would be cutting away next years flowers. Any help is appreciated.

Also is the any hope for the one in the pot ?

 

Do you know the names of them @David McCann ? They all have different eventual sizes, and some can become huge in the right conditions.
They can certainly be pruned, but you'd do that after flowering. If you cut them back in autumn, you'll remove the forming buds and won't get flowers in spring.

The one in the pot will be struggling for health as the pot is very small. They're shallow rooting shrubs, so prefer width rather than depth if potted. In a pot, any plant needs more attention, so you also have to make sure that fresh soil/organic matter is regularly added to the mix - usually by removing the top layer and adding more.
I think that would be difficult with the pot you have, so it might be best to get something wider for it, and move it into that. You can do that just now. It should be fine for a while if you can do that.
The other problem is that they can get a bit dry in containers because the foliage prevents rain getting in, so you have to check them frequently, especially if you're not in a consistently wetter, cooler part of the country.

 

?? Your further explanation would be welcomed

 

Thank you for your response, really useful.

I've lost details of the one in the potted some time ago,the other one is Ponticum Variegatum (thought I had lost that label as well, but just found it). On the potted one, am I right in assuming there will be no growth from the wooded part of the stems now, and I will have to work with the shape it is ? I also assuming that on both I can only prune to the green growth/wood

 

Just looked at the photo, don't think it does the pot justice, but I get what your saying

 

Not as my first impression then:
that you were wishing to create a mini peat bog to maintain low ph value;
oh what a let down.....

 

It's also important to position potted shrubs in the right place. Near house walls can be much drier, depending on the aspect. Terracotta also absorbs moisture far more than other materials, which can prevent the plant getting enough. You also need to use a soil based mix for it - not just compost. They don't desperately need acidic conditions, and are perfectly happy in neutral soil as long as it isn't too alkaline, but you can either buy one of the J. Innes mixes designed for shrubs, or mix your own using mostly soil and a bit of compost. Drainage is important, because, despite enjoying any amount of water that falls from the sky, they don't appreciate water logging. If it's staying on the paving, some pot feet to keep it off that will help too.

I wouldn't be hasty in wanting to prune the other one though - let it have time to settle and establish, which will take until next year. It's only been planted a short while. Shrubs aren't instant - they take months to get their root systems settled before they start growing.

 

I'm looking at that pot.
Is it slightly narrower at the top?

If so it could be a hammer job to get it out in one piece.

I agree, it needs to go in the ground.