I planted 5 swamp hedging cedars last year to form a hedge at my property line. However, recently when I start to spend more time in the yard I feel two of them were probably planted too closely – They are about 18 inches apart (is the proper spacing 2-4 feet?). They have grown a few inches since I planted them, reaching about 8-9 feet, trunks much thicker than last year, meaning they are estimating well I think. Is it worth to dig them out and replant them? I would need to replant 4 of them to correct the spacing. And would they take another year to establish once moved?
It does sound like your cedars are establishing well. Since they are only entering their second year, the root balls will not have expanded greatly and therefore you could dig them up and replant them. However, those plants may not catch up to their neighbours this year, since there will inevitably be some transplant shock and 18″ apart is really not too tight for a hedge. (Some people plant them root ball against root ball but we would not recommend that.)