I love Easy Grammar! In our homeschool we didn't use a grammar every year. We worked on grammar in writing and all five of our children were required to complete the basic Easy Grammar curriculum. That can be done in less than one school year. For us, sixth or seventh grade was a good time to get it done. It can even be done in high school.
There are many more workbooks available besides the basic Easy Grammar if you feel the need for practice and review. Each family and each student is different. Anyway, you'll find whatever you need for grammar by this publisher.
The book we used was the plain "Easy Grammar: A New Approach to Grammar that Works!". It is a red book and was the original from which all the other workbooks that they offer are based. The newer workbooks may have improvements, but the original was just what we needed.