Each item in Minecraft has a unique ID assigned to it, known as an item ID, this can be used in commands to spawn the item into the game. The item ID for kelp plant in Minecraft is shown below:
The Kelp Plant item can be spawned in Minecraft with the below command. Cheats must be enabled before this will work.
This is the block that takes the place of kelp when it grows. Kelp can grow as high as there is water above it.
|Max Stack Size||64|
|Min / Max State IDs||8436 - 8436|