As you explore the islands, you will be chopping and clearing plenty of grass. Most of the time when you clear grass you will collect tufts of grass, but sometimes you will get extras like energy, a clover, caoutchouc, a spike, or a potato!
Grass is regenerative; to get more information over how and where it regenerates, see the article Do Resources Regenerate on Home Island?
The main advice here is to clear as much grass as you can on as many islands as you can to get as many extra goodies as possible.
To learn more about where you can find grass that will give you extra goodies when you clear it, check out the Archipelago Islands section.