Sometimes English teachers focus less on grammar and more on reading because students enjoy that more. However, in today's world with texting so prevalent, correct grammatical structure has suffered. Students write like they talk which leaves much room for improvement. Formal writing requires a strong knowledge of grammar and usage.
Have you considered using technology to teach grammar? I recommend reading "Practice Grammar With Technology," a Tech & Learning blog (April 24, 2013), that lists some technology enhanced tools to teach grammar.
After you take a look at these resources, please share which ones you have used with your students. How did the use of one or more of these resources help your students learn grammar?