Tractate Kilayim - Chapter 2 - Mishnah 4 כלאיים פרק ב׳ משנה ד׳

[His field was] sown [with grain, or pulse, or garden-seed], and he changed his mind and decided to plant it [with vines], he may not say: “First I shall plant [the vines] and then turn [the soil],” but he must [first] turn [the soil] and then he may plant [the vines]. [If it was] ‘planted’ [with vines] and he changed his mind and decided to seed [with grain, pulse or garden-seed], he may not say: “First I shall sow [the grain etc.] and then I uproot [the vines],” but he must [first] uproot [the vines] and then he may sow [the grain etc.] If he wants, he may cut down [the vines] to less than a handbreadth [above ground], and then he may sow [the grain] and later, he uproots [the vines].