The documentation indicates the time.Tick leaks ('be aware that without a way to shut it down the underlying Ticker cannot be recovered by the garbage collector; it "leaks"'). I'm assuming this refers to the channel. However, there appears to be no way to cleanup a Timer, either: You can make sure it doesn't fire but you can't close the channel (receive only).
The code for it doesn't contain a close call. runtime.deltimer (which is the underlying mechanism for Stop) doesn't touch the channel either.
No matter what, does Timer always leak?
The only cleanup that matters is performed by calling Stop (as mentioned by @JimB).