This research investigated the use of blogs to promote collaboration between teaching English to speakers of other languages (TESOL) teacher candidates and Adolescent English teacher candidates and to sensitize them to the writing demands placed on secondary English language learners (ELLs). Blogs offered an authentic experience for teacher candidates to interact with each other and with ELLs. Qualitative analysis showed Adolescent English teacher candidates' desired more such fieldwork that would put them into direct contact with ELLs. TESOL candidates reported learning about the demands of high school academic writing through the tasks and the blog responses posted by their Adolescent English counterparts. Affordances and limitations of blogs as a tool in teacher education for ELLs, as well as the need for TESOL and content area teacher candidates to participate in collaborative fieldwork to strengthen instruction for ELLs, are discussed.