Hi, We have a fine feathery leaf drooping red Acer about 12 yrs old. Over the last couple of years a couple of branches have died off although it has been poly tunnelled over the winters, this year we appear to have lost another. Getting worried as it is my favourite plant and can't afford to replace it. The plant has been repotted a a few times and last year into a large pot with of course ericacious soil. Any advise please ?
Where abouts in the country are you? They can be fussy plants especially when exposed to too much sun or wind. Make sure the ericaceous compost is mixed with another loamy one or add sand to improve drainage. Maybe try bubble-wrapping the pot in winter too as poly tunnels are not always frost free. Could be a type of verticillum wilt unfortunately in which case if it is your favourite plant then maybe research trying to take cuttings of it.. they do take a while to root though!
Here's a good link: http://homeguides.sfgate.com/prevent-twig-dieback-japanese-maples-22287.html
I'm up in Scotland and just bought an Acer palmatum myself, will have to see how it gets on in the cold (although winter non-existent this year)