With my older kids, I did what you're suggesting. They were both avid readers and the oldest is a writer. So, for the oldest, I waited until high school, handed her "Nitty Gritty Grammar" and "More Nitty Gritty Grammar." That was all she's ever needed.
My second needed a bit more than that, my third needed a lot more, and my youngest is along for the ride.
I came across a curriculum called "Growing With Grammar." It is a separate program. I started the three youngers on the same level, level 6. We spend 10-15 minutes a day. It's a lot of fun, there is good discussion since we do it together, and we are all learning a lot.
Robin, wife for 22 years to a wonderful man, and mama to 20yo Belle; 18yo Kitty; 14yo Princess, and 12yo Boyo.
Words for 2015 and 2016 and probably forever: Be her.