Protect them from rabbits over winter, or you will have no hemlocks in the spring. Hemlocks grow natually in full shade and don't need much supplemental care, they don't like drought so water if next summer is dry.

Here is a link that might be useful: Hemlock Care

They also need protection from deer. Be on the lookout for wooly algedid. it's a killer.

wooly algedid control - spray with dormant oil before the trees buds open and when appropriate spray with insecticidal soap.