There's another way to get to flower a bit faster!
Stone + water = sand
Sand + water = clay
Wood + stone = dirt
Dirt + clay = planter
Planter + water = flower
Uses 2 stone, 3 water, 1 wood (6 elements total) . The terrarium route uses 2 stone, 2 water, 1 fire, 1 air, 1 wood (7 elements total). Interesting though that the terrarium route uses a more even spread!