field, farm, garden, (kokuji)
畠 centers on a cultivated piece of land: a field, farm, or garden where crops are grown. It is a kokuji created in Japan to express this idea.
畠 is a kokuji (Japanese-made kanji) combining 白 (white) and 田 (rice field), likely to represent a dry field or upland farm as opposed to a flooded rice paddy.
A white 白 rice field 田 is a dry field or garden where crops are grown. Picture a sun-bleached white field ready for planting.
For はたけ, imagine a farmer wearing a hat (はた) and carrying a rake (け) while working in the field: hat + rake -> はたけ.