If SharePoint Log is growing large – Things to consider :

If you are going to stick with Full Recovery, make sure you're doing *Transaction Log* backups, this is what empties the TLog.

Also, do not run Update Statistics or Reindex jobs from SQL Maintenance Plans against SharePoint databases. SharePoint has specific Health Analyzer rules (timer jobs) that do this activity for you.

If you're in Simple recovery mode then the log files should automatically empty whenever SQL thinks it's come to a sensible stopping point. If you're in Full recovery mode then the log files will continue to grow until a Full backup is taken. A second backup will then empty the logs out.

If you need to be in the full recovery model then run two full backups. The log files will probably not reduce in size immediately and a shrink may be required. You will then need to schedule a backup schedule to prevent the log files re-growing on you.

It is better to check backup logs regulary and it is needed to run a manual backup if it fails.