once the leaves have died back

I just leave my tulips in the ground and they come away again the following year - I didn't know you were supposed to lift them!

We prefer not to lift tulip bulbs but I did so today because these were in the wrong place. Wait until the leaves have died back but the old flower stem is still visible to identify where they are!

Sheilar as Bulba. says we don't normally life ours either.