I dropped a significant table in my database and has been trying to use a 'flashback ... to before drop' but keep getting the error as shown below

SQL> drop table plants;

Table dropped.

SQL> flashback table plants to before drop;
flashback table plants to before drop
*
ERROR at line 1:
ORA-38305: object not in RECYCLE BIN


SQL> flashback table PLANTS to before drop;
flashback table PLANTS to before drop
*
ERROR at line 1:
ORA-38305: object not in RECYCLE BIN