Material timeline for Foliage

I have my basic foliage and its material…
I already have set up a scalar parameter so that I can change the looks : Become fluorescent at night…
Also the reactiveness to the player collision…
But in order to program it (so that it transitions in the night) I must use a timeline which I cannot use as foliage?

link text (look at their feet)

How do I go about creating this?

Thank you

The night one you could probably do from he level blueprint. Just use a get all of class then use your set scalar through a timeline from there

In all class do I put the Material? does it have to be instanced?