Underground filming and everything. Strangely hypnotic.

I found it very soothing to watch.

Neil Bromhall filmed this video, and explains the timeline of the tree's growth:

The acorn was collected in September and filmed in an underground set using a 2 hour interval between exposures.

The acorn split soon after it was planted and continued to split during the winter months. In January the first sign of root growing could be seen followed in February by the emergence of shoot.

In March the shoot broke through the soil surface.

The leaves formed between March and April.

This is an example of hypogeal germination.

Source: http://io9.com/watch-an-acorn-turn-into-an-oak-sapling-in-this-eight-m-1684081907