Excel Formula: Create vertical list by returning column header of each non-blank cell in a horizontal range across multiple columns

[haruspication]

Starting in H2, I'm trying to find the correct excel array/formula that will scan the horizontal range $B2:$D2 and return the column header of each non-blank cell in the range in the order they appear, and then move down to $B3:$D3 and do the same, etc. (The dates listed in Column H would then correspond with the crops listed in Column G.)

I appreciate any help in the right direction.

	A	B	C	D	E	F	G	H
1		2-MAY	9-MAY	16-MAY	TOTAL COUNT		CROP	PLANTING DATES
2	Crop1	1	1		2		Crop1	2-MAY
3	Crop2		1		1		Crop1	9-MAY
4	Crop3				0		Crop2	9-MAY
5	Crop4		1	1	2		Crop4	9-MAY
6							Crop4	16-MAY
7

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To see ARRAY formula in Column G, see: Skipping blank cells in list based on non-blank cell count in each row