melon_stem_fruit.JSON

{
    "parent": "block/stem_fruit",
    "textures": {
        "stem": "resmel:blocks/melon_stem_disconnected",
        "upperstem": "resmel:blocks/melon_stem_connected"
    }
}


melon_stem_growth0.JSON (Same for 1-7)

{
    "parent": "block/stem_growth0",
    "textures": {
        "stem": "blocks/melon_stem_disconnected"
    }
}


diamondMelonStem.JSON
{
  "variants": {
    "age=0,facing=up": { "model": "resmel:items/melon_stem_growth0" },
    "age=1,facing=up": { "model": "resmel:items/melon_stem_growth1" },
    "age=2,facing=up": { "model": "resmel:items/melon_stem_growth2" },
    "age=3,facing=up": { "model": "resmel:items/melon_stem_growth3" },
    "age=4,facing=up": { "model": "resmel:items/melon_stem_growth4" },
    "age=5,facing=up": { "model": "resmel:items/melon_stem_growth5" },
    "age=6,facing=up": { "model": "resmel:items/melon_stem_growth6" },
    "age=7,facing=up": { "model": "resmel:items/melon_stem_growth7" },
    "facing=west": { "model": "resmel:block/diamondMelonStem" },
    "facing=east": { "model": "resmel:block/diamondMelonStem", "y": 180 },
    "facing=north": { "model": "resmel:block/diamondMelonStem", "y": 90 },
    "facing=south": { "model": "resmel:block/diamondMelonStem", "y": 270 }
  }
}

diamondMelonStem.JSON
{
  "parent": "block/stem_fruit",
  "textures": {
    "stem": "resmel:blocks/melon_stem_disconnected",
    "upperstem": "resmel:blocks/melon_stem_connected"
  }
}