fence would be good but I have had damage from rabbits,woodchucks,beaver, mice,voles,&even vulchers as well as deer. My thought on transplanting is that even if you get it done before they get to large, you'll still damage roots & at the very least stunt growth. It would be work(time) as well. If your not spending much ,$ on saplings that's different. Most of my maple saplings have cost $14.00-$25.00 each. I have planted some free ones, but not many. I have found success just planting some everyyear therefore spreading out the work, & money. Also if you plant then have a record drought it's hard to save them. If there's fewer to water, easier.