💧Paint water. Life spreads from wet ground on its own: dirt → grass → shrub → forest. Water soaks back into your supply as it settles — you won't run out for good.
🪨Rock & sand are barren — nothing grows there, and they block the spread.
🏞️Pale riverbeds carry water — drop water in one and it races down the whole channel. Read the land.
🌳At 8% green the Grove unlocks. Tap it on greenery to expand it — water alone won't fill the map.
♻️Recycle reclaims placed water instantly (or just wait for it to soak back). At the end, recycle it all to leave no trace and win.