If you want to get them without using ferns you need a iguandon medium crop plot and a rockarrot put that rockarrot in the iguandon tap the iguandon get the seed put it in the medium crop plot and wait for rain get poop put in the medium crop plot then wait for the seed to grow then you have inf rockarrot recommend to do in rain

Want an easy way to get rockarrots? Tame two-three mesochopitus, put them on wander, and they’ll collect lots of Berries, seeds, and even crops & crop seeds, rockarrots can be found on jungle ferns, easiest way to get them is to harvest 5 ferns, you should have about 2-3 rockarrots from 5 ferns

Use any herbivores tames to harvest them easily