There is a wide proliferation of journals, both print and online, but a tendency towards the shorter: poems of a page or less, sometimes with a maximum line count explicitly stated in the submission guidelines.
Especially in the age of social media, there is a tendency towards shorter and aphoristic poems, poems that start and end neatly and can be easily shared. There aren't nearly enough venues publishing long poems.
+doc is a semi-regular journal focused on longer poems and poem sequences, including visual poetry. The definition of "longer" is kept intentionally vague in the hope it may fit your work.
Submissions are currently open. To submit, send an email to Julian Day at jcd748@mail.usask.ca with "+doc" as part of title and the piece(s) as a .docx/.doc attachment. Don't worry about a cover letter! Maybe just say hi? I can't wait to read your work (unless it's racist, homophobic, etc, in which case it will not be considered).
The first issue is planned for later in 2021.