Posted: 05/11/2017 at 22:08
I had a sango-kaku in my last garden and every winter there would be some die-back and I would need to cut out dead grey stems in spring. In hot or very windy weather they do transpire a lot of water from their eaves so need extra drinks to keep their foliage looking good.
As FG says, it's hard to establish an older tree so, give the roots a good drink now, scatter some bonemeal around to feed the roots thru winter and then give it a generous mulch of well-rotted manure or garden compost. Next spring, when buds start to open, make sure it is given some blood, fish and bone and plenty to drink in dry spells.
I think moving it will be risky but, if you must, do it soon and water the roots well to minimise damage before you dig it up and take as much root ball as possible. Prepare the new hole well and water it in well after re-planting and all through the next growing season. It may be simpler to erect a trellis wind break or plant something between it and the prevailing winds.