So first off, when the spell is cast, the plant is mechanically given an IQ of 9, an additional 6 HT, and a move of 4. All together, this could be represented as the following template
Animated Plant Spirit
Secondary Characteristic Modifiers: Basic Move+4 
So this template is very simple, and very expensive. Note that the spell that gives the Animated Plant Spirit Template will be mana sensitive, so that means that this will have a 10% discount when casting, so it will add 2340% to affliction.
The completed spell looks like this:
Animate Plant (+2290%): Affliction(Sorcery -15%; Advantage, Animate Plant Spirit +2340%; Increased 1/2D, 10x, +15%; Fixed Duration, 3 Minutes, +0%; Accessibility, Only on plants with an IQ below 6, -50%) 
This spell costs 239 character points and lasts for exactly three minutes.