There is a young japanese maple tree, approx 4cm in diameter at the trunk. It was snapped/broken off at the base 4 days ago. It has been outside since then,laying on the ground,had endured one night of -2c until last night when I brought it inside. Outside was 0degree. It is a healthy tree and the internal trunk LOOKS healthy and moist. Can it be saved? and what do I do to try and save it? (amateur gardener here). Thank you so much for your help. Tanya

If you have a bud remaining on the truck, it may grow a new shoot from there in the spring. You should prune off the break so that all surfaces as clean. The maple may also put up shoots from the root. As far as the top which is broken off, very unlikely that it will sprout in water after enduring so much shock. Ditto on starting a twig with rooting compound. But no harm in trying! Let me know what transpires.