Acer in large pot Brought a young tree last month from a specialist supplier. Repotted it into the larger intended permanent container adding a mixture of multipurpose and ericaceous compost, with shingle at the bottom to aid drainage. At first all was well: it arrived in bud and over about a fortnight the pink edged tips of the leaves were starting to emerge. Then it suddenly started to look sickly - just after a freaky warm sunny day, so it might have got a little scorched while still tender. Within a week, knowing a harsh frost was due in a day or two, we brought it into a cool conservatory for protection (bright but in a corner out of direct sunlight), giving a little water when the top inch of medium seemed dry. However, the leaves continued to shrivel over the next week. Not wanting to deprive it of natural air/rain/dappled sun for too long, we then put it outside again but in a less exposed position than at first. So it's been through a lot in just a few weeks! How do we know if it has already died, or what else can we do now to give it the best chance of survival?
With a sharp knife gently scrape away a tiny bit of bark on one of the twigs (hold the blade at right angles to the bark - be gentle!). If you see green, the tree is still alive. If you see brown, try another twig. Green is alive, brown is dead. You can always practice this on another shrub in your garden that you know is alive.
Well from the latest photos, it's clearly alive and survived its ordeals. What concerned me was your description of how you watered it while it was indoors... that is a very large pot, and likely the rootball only occupies much less than a quarter of the soil in the pot, so ongoing, make sure it is watered thoroughly when it needs watering,enough for the water to run out of the bottom. The risk with planting into too big of a pot initially is that,although the soil may seem damp, it might not be damp all the way through,so the rootball of the plant does not get sufficient water for the first 3 or 4 months. It's also important not to keep it too wet,so having good drainage from the pot (without a tray or anything beneath) is critical.
Now that it is back outside, it should be left there permanently - these trees prefer a sheltered spot that is not windy, with dappled or partial shade, or at least not in direct sun between 11 and 3 during late spring and summer.