327. Arbor Day: The prohibition against working trees during Shemittah
…your vineyard you may not prune… (Leviticus 25:4)
Not only may we not work the land during the Sabbatical year, we may not actively cultivate fruit that grows on trees, either.
The reason for this mitzvah is identical to what we said in the previous mitzvah: during the Sabbatical year, we do not work the land as a reminder to ourselves that God is the One Who makes the produce grow. That’s as true for olives and oranges as it is for wheat and barley.
This mitzvah applies to both men and women but only in Israel. It is the subject of the tractate of the Mishna called Sheviis and it is codified in the Mishneh Torah in Hilchos Shemittah. This is #221 of the 365 negative mitzvos in the Rambam’s Sefer HaMitzvos and #23 of the 26 mitzvos that can only be performed in Israel according to the list of the Steipler Gaon.