Evan, on resizing pictures I open mine in Picture Manager (microsoft works), then select Edit, then Web page option, then Compress pics. Save. and you are good to go. (Hopefully, I didn't leave out a step there. But it should walk you through it.)
On the Hemlock question. Often times you can help a conifer "choose" a new leader by picking a suitable lateral and tying it up with a brace. Pictures will be very helpful in determining if this is possible in this case.
If you do not assist the tree, the tree may end up with several codominant tops which could present issues in the future.
I firmly agree with Kennertree on watching the fertilizer! Be careful there.
Sylvia