RE: What is an ice spike and why are there two of them in my watering tub?

Have you read Terry Pratchett's witches?
There's a scene where they go to break someone out of a dungeon in a castle
One of them puts her energy into the ancient oak door, reminding it of all the springs it has missed, and it bursts into life; coincidentally opening the door.
Granny Weatherwax says something about the Stones being harder to reach but good if you can get through to them...

I think your two spikes are maybe representing the leaves/trees, and the rocks, waking up for the new year?