Like Math, the language arts of grammar, punctuation, spelling, and vocabulary are rule based skills which can be successfully taught with a traditional textbook or workbook style curriculum. Most language arts curriculum include reading comprehension and some amount of writing. Our approach has been to rely on language arts curriculum for the skills and challenge the student with reading a variety of material and writing in a variety of styles such as essays, lists, poems, etc.
For our general curriculum, we have used Learning Language Arts Through Literature (LLATL) for years. It uses a balanced approach with a variety of lessons and activities. We don't do all the reading and book studies, as those are covered in the more general subjects such as Bible, History, etc.
For a writing curriculum we use Writing Strands. This introduces various types of writing – prose, technical descriptions, poetry, dialog, etc. in interesting lessons. Much of this is covered in LLATL but the extra emphasis on writing is welcome. Most of the writing done is outside of any language curriculum and consists of outlines or essays based on reading assignments, special activities, or other events in our family life. See the Writing subject page for more details.
The LLATL "Tan" book is recommended for 6th grade. The book has 36 lessons, each lesson consisting of 5 "day" assignments followed by review. This fits the typical 9 month school year. We aim for one lesson each week, usually combining day 5 with portions of the review section. You can omit other parts of lessons and not miss essential material. Remember language arts is learned through the Reading, Writing subject areas that are done in addition to daily LLATL work. Also, LLATL is a comprehensive curriculum for elementary through high school with a different book for each year. So material you may deemphasize in one year will be seen again in the next. Basically, you can relax as it all "averages out" over the years, as long as you are not neglecting major subject areas for months. The provided lesson schedules for months 1 and 6 show a typical progression in the LLATL Tan book throughout the year.