EastScape Wikibuilt from the game itself

Brineberry seeds

Where to find it: Glasswater Wastes (Saltglass Stalker).

“Plant them on your island (Harvesting 108). They grow brineberry, and give their seeds back. Saltglass Stalker drop them.”

Dropped by

MonsterLevelHow manyChance a killRoll
Saltglass Stalker11111.3%Own roll

Grows

Plant it on your island's plots (Harvesting 108): ready in about 600 minutes, logged in or not.