I know about the 'r' and the 'u' keys in NEI, and they def aren't working for this Essence. Maybe my game is messed up? I left it running while I slept because I tried your serpentine pattern, but it is slower than molasses without sprinklers and Agricarnations. I planted a 1-1-1 Iron seed 9 hours ago and it's only at 3-3-2 with a total of 5 plants in those 9 hours.
Minecraft farming is not time based, it's based on random ticks. To grow things fast, you need to plant multiple seeds, not one seed and wait for it to tick. You plant a lot, and wait for 80% or so to grow, which is very very fast even with 1/1/1 seeds.
You get a total of 3 seeds from the quest, plant them all, leaving room for each to spread. You should have some magic fertilizer left from other quests. Fertilize each seed until its fully grown, and leave them (or make yourself 8 essence as well if you have enough fertilizer, its more than worth it at that point). After a short while come back and see if they have spread, fertilize the new plants etc.
There are also vanilla tricks you can use to speed things up (plant in rows etc). Ignore the horrible advice about planting one seed and mutating it while you go to sleep, you don't need that at all.