Hilchos Shemittah v’Yoveil 4:5

Safiach from shemittah that enters the following year may not be eaten. It may not be uprooted by hand; rather, one must plow the land in the regular way or let an animal graze there.

Hilchos Shemittah v’Yoveil 4:6

Safiach from shemittah is prohibited in the eighth year from Rosh Hashana until Chanukah; it is permitted from Chanukah and on. If, after shemittah, someone plants the safiach of shemittah, what grows from it is permitted.