Maybe "Preferred Water" and "Preferred Soil"?
KentPfeiffer said:I vote for an actual range in the pH field.
If we keep it in checkbox form it will let people use the advanced search for find plants that match. Maybe the solution is to have the various pH ranges as checkboxes?
We'll do water needs in checkbox format (I think that's what you're proposing, too)
I see your point on the growth rate. We may just leave that out.
Your other suggestions have been incorporated into my post above.