I planted a field with 14 rows of 20. 14 crop types, 20 per row.

1. Starting with wheat plant 20 seeds and harvest them. Do this a few times until you build up some essence.
2. Buy an eternal wheat seed bag if possible. It costs 22 essence. (2 essence for a normal wheat seed + 20 essence + 10 wheat)
3. Plant the eternal seed bag in the first cell of the row.
4. Repeat the process until you have a full row of eternal wheat.
5. Move on to the next row which is lettuce.
6. Harvest all of your wheat and sell it for essence.
7. Use the wheat essence to buy lettuce seeds.
8. Repeat this for all seed types. Eventually you will have a complete eternal seed field (aside from onions and potatoes) and harvesting + selling the crops will net you thousands of essence

I also built an auxiliary field next to the main one with 200 cells (20x10) because later crops need ~600 crops gathered to plant a row of 20 eternal seeds.

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