It is usually very traumatic for seedlings when they are transplanted. Some are hardly affected while others really suffer. Kind of like kids first day at school right? WhaT I find is excellent for transplanting seedlings ,& just about everything is SEAWEED EXTRACT. If you soak the roots in a small amount mixed accordingly with water for 24 hrs prior to planting out, or potting on, then water them in with it they should carry on growing as though nothing happened. Its useful for big plants too, even small saplings you discover in the wrong place.With those, water them thoroughly 1st then dig them up with as much root ball as poss.It pays to put them in a pot with good potting mix & sit it in a shallow container. Water well with the diluted seaweed extract & leave pot in shallow container until all signs of wilting has gone. Pays to plant out in a few months once the tree roots are visibly growing at base of pot. In Australia Seaweed extract is available in all nurseries, hardware stores,& super marts.I hope its available where you live.