Based on this we can also answer the Bach’s question on the Tur regarding the sechach of a sukkah. For based on this, placing the sechach sideways is indeed fulfilling the requirement of placing it the way it grew.
However, Tosafos (Sukkah 31b) and the Pri Megadim (651: Eishel Avraham 22) say that holding an item sideways is not a fulfillment of holding it the way it grew. We can assume that the Bach, who asked the question on the sechach, would agree that holding or placing an item sideways is not considered a fulfillment of placing it the way it grew.
Similarly, we can also answer another question. The b’richim (horizontal beams) of the Mishkan were placed horizontally. How was this acceptable? Since they grew vertically, they should have to be placed vertically. But based on the Acharonim, who opine that sideways is also considered to be the way it grew, we can understand how the b’richim were allowed to be placed horizontally.