HHGames/data/herohost/worldgen/configured_feature/patch_grass.json

{
  "config": {
    "tries": 48,
    "xz_spread": 6,
    "y_spread": 1,
    "feature": {
      "feature": {
        "config": {
          "to_place": {
            "entries": [
              {
                "data": {
                  "Name": "minecraft:short_grass"
                },
                "weight": 3
              },
              {
                "data": {
                  "Name": "minecraft:fern"
                },
                "weight": 1
              }
            ],
            "type": "minecraft:weighted_state_provider"
          }
        },
        "type": "minecraft:simple_block"
      },
      "placement": [
        {
          "predicate": {
            "blocks": [
              "minecraft:air"
            ],
            "type": "minecraft:matching_blocks"
          },
          "type": "minecraft:block_predicate_filter"
        }
      ]
    }
  },
  "type": "minecraft:flower"
}