Grass Seeds trip people up because chopping regular grass gives you nothing — you're meant to look up. They drop from one specific plant, and you'll need them for the Omni-Tool shovel. Here's exactly what to harvest and where.
Seeds come from Grass Flowers only — special stalks that stand taller than the surrounding grass, with a distinct pointed seed cluster at the very tip. Once you've spotted one you'll see them everywhere; the habit to build is looking up, not down.
The most reliable early source is right outside the Snackbar Ranger Outpost — convenient since you'll be passing through it anyway.
Grass Flowers spawn throughout the map wherever there's tall grass. Once you can recognize the seed-head silhouette, you'll never be short.
Two main jobs:
Kitting out the Omni-Tool? Here's the rest of the backyard lookup list.