I don't like containers because of the possibility of ant infestation apart from all the watering etc. If the container is an ants nest with a tree in it rather than a container with a tree in it that also has ants then this could be the problem. The mining of the ants may mean the roots have been dry due to very good drainage caused by the tunnels. This in turn would reduce the nutrient uptake of the roots. Ants wouldn't tolerate roots blocked tunnels so they may have removed new root growth. Ants in themselves are not too much of a problem but their activities are. I would suggest if there is no green to indicate the food system is still there and it hasn't produced any growth this year you're going to need to buy something else in memory of it. I'm guessing in part but it doesn't look good.
Best Wishes.

OH Ninja, that is sad....I hope someone suggests a way to revive it, but if there is no green ring, and no growth at all by mid June, I fear it may have died....luckily it is a plant, and you can replace it with the same one, and it will still remind you of your first plant purchase together. Sometimes we just have to accept losses....sorry! I hope that doesn't sound insensitive...I understand that it means a lot and I do hope it recovers, but I have no idea how...good luck! Karen :D

Sorry but it really sounds as if your acer palmatum has gone to the home for happy plants in the sky. If you have to keep the new one in a container put something like J-cloth over the holes in the bottom and raise the container up on feet - both of these will help to keep the ants at bay.

Actually I think this is a watering problem ...Ants will only nest in dry conditions ...There is hope WATER WATER WATER...ithink drought has been the problem.

Oh, well....a note of hope....worth a try for sure!

I thought Norfolk had been getting the monsoon - no? Mind you even when it has been raining a lot trees in containers can need water.

Oh yes, we've had loads of rain here, but I still have to water, as the rain bounces off the leaves on to the ground.

Thanks everyone,
I'll try everything and hope for the best, the jeycloth and feet is a good idea for future reference. Pimpernel - I like your optimistic reply, I'm not ready to give up on it yet!

It is all about care when using containers..they are easy to 'forget' especially if you have had it a long time and it's always OK.. The soil compacts over time even in a pot. I would spike it all over but carefully and soak it ( really soak it) for a couple of times a day for two weeks. Then I would loosen and replace with as much ericaceous compost as I cn get in and continue to water daily.

Just seen your reply...Very Good Luck to you,

Have you got it in dappled shade? I understand that's the natural habitat. Mine is a a similar age and also in a pot but it is under tall shrubs. I have sorely neglected it but it has lovely fresh growth this year. Maybe I've just been lucky but I will certainly take more care of it in future as, like you, I would hate to lose it. I do hope yours survives .