I just posted what Google showed when I ran the image. I hope you all can discover what it is!
Ok, Bratti, if it’s marijuana, do you want to buy some or can you push a bit for me?
Candy, 
l do honestly, appreciate your help and investigations. I also appreciate everyone else’s help too.
It might be best when the flowers comes out.
Bratti, lt would be great if you and Mups are right as l love Rhododendrons and Azaleas.
About three of mine have died for no reason lately but this mystery plant wasn’t growing anywhere near them.
It looks a bit straggly for my liking. 
Here’s a close up of healthy Azalea leaves
As well as an unhealthy Rhododendron.
I don’t think it’s been identified correctly yet. Artangel, perhaps you could put up another photo when the bud opens. By the way, do you feed seed to the birds?
No l don’t feed the birds, Juna. I did once and had rats dancing on my lawn and climbing up the bird station thing!
The pest control man told me not to feed the birds as it attracted the rats.
Art, can I have some info please?
How did you come by this plant?
Did you dig it up from somewhere, and pot it up yourself?
If so, when was that?
I ask because I am wondering how long it has been potted. Was it only this year or has it over-wintered in that pot?
Has it grown much, or was it that size in the first place?
At the mo, I still think it looks like the Rhodedenron/Azalea family, but I’m still thinking as something is not quite right.
One last question please.
What is it planted in? - Garden soil? Multipurpose? Ericaceous? John Innes? Or none of those?
Thanks.
P.S. You say three other of your Rhode’s are dying.
That seems too much of a coincidence to lose three together.
May I ask whether they in tubs or in the ground, and are they young plants or huge old established ones please?
Ta muchly.
Hi Mups, l will answer as accurately as I can.
I found it growing in the soil in my garden, probably, a year ago. It was tiny.
I dug it up, put it in Bloom’s the garden centre, own brand multipurpose compost, in a pot.
I kept it in the greenhouse but recently, l took it out to keep it nearer the house so that l could water and feed it regularly. It seems to have grown really quickly to the size it is now.
The Rhododendrons and Azalias that have died were in the ground, in an area where there are lots of trees behind them.
Two were here when l came to live here. The lady who planted them. had lived here for about ten years. The other three were ones l planted within the last fourteen years. I saved another, a small one and that’s in a pot in the greenhouse.
Alongside them is a ‘Harry Lauder’s Walking Stick’ Corylus Hazel that has really gone a bit wild. Whether or not, that has sapped all the goodness out of the ground, l don’t know?
I hope this can help you, to help me!
PS. I have just found a pic of when they were alive…
Is that your garden Art? It looks amazing.
By the way I think I am going to dream about your plant. It looks so familiar but… maybe I am thinking of my oleanders but it’s clearly not an oleander. I hope you get to the bottom of this and if you do find that it’s mary jane then please do set up some ebay outlet so we can all appreciate it!
I wonder if the plants that died got their roots down into something they didn’t like. Another thought is they didn’t get enough moisture because of the trees, unlikely I would think.
Cor, Thanks, Annie. l love my garden, it is too much for me really but l never want to leave here. I stare at it and gasp at how lucky l am.
I hope your dream can solve the mystery! Is Mary Jane, you know what? I have never heard it called that before!
Does it look anything like this plant, Art?
Mags, The bud on my plant is only small and not a stem with lots of buds on it. So l don’t think it’s the same.
Thank You for looking and posting it though.
Back to the drawing board then…
Art, thanks for the info.
I have been pondering over the leaves of your plant, which look like they are in sets of five?
The only other thing I can think of is a baby Horse Chesnut tree. These have the 5 leaves, although that still doesn’t look quite right.
The pointed looking bud still looks like the Rhode family to me.
See what you think anyway:
http://guide.makebonsai.com/photos/small/Aesculus_hippocastanum_sapling.jpg
P.S. Lovely garden by the way. 
It might be worth trying the Flora Incognita phone app. A friend showed me it last night and it works quite well. You open the app, take a pic of the plant and it goes through a database of 4,500+ plants and shrubs.
I tried it at my volunteer work place where I was sorting out a greenhouse and a small patch of garden. There were 5 or 6 grey plants growing (no flowers but there was a sort of bud unfurling) and I could tell they weren’t weeds but no-one knew what they were. The app recognised them as poppies.
That crossed my mind too Mups.
It’s a annoying because I feel as though I know it really well.
Sorry Juna, l must have overlooked your reply. I think the trees took all the goodness out of the ground.