WOW! I love your work. Several of these are on my favorites!
As we were evaluating your designs, we realized that our brand might not be clear enough. The name GRO is short for growth. The rx in the US stands for "prescription". A "prescription" is something a doctor gives you to make you feel better (at least in our country). So the tagline might be "Your solution (prescription) for growth".
We are looking for a design that is cool (hip), unique (different), high energy, and one that says "our company is THE solution if you want to grow your business.
I hope that helps! Keep up the great work!