Wednesday, August 01, 2007

Tu b'Av - chag ha'ilanot?

Is it too late for a Tu b’Av post? The first Mishna in Rosh haShana tells us that 1 Tishrei is the new year for netiyos, plantings. Assuming chodesh echad bashanah chashuv shanah, a plant must be around for one month in the year for it to count as a year, the plant must exist from Elul. On top of that one month, it takes (according to some Tanaim) 2 weeks for a plant to root. The Bartenura therefore writes that to count as a year of growth before Tishrei, planting must occur no later than Tu B’Av.

Achronim ask: the Bartenura’s cutoff point seems to be off by a day, as miktzas hayom k’kulo would allow one to plant on 16 Av and still make it!

The Noda b”Yehudah (II: O.C. 84) answers: miktzas hayom k’kulo only applies when counting days, i.e. it is a din in the shiur of what constitutes a "yom". When it comes to planting, the shiur is not 14 days, but rather is two weeks, which is not the same thing - you can’t use miktzas hayom to complete the shiur of required weeks.


  1. Does he give a reason for the distinction?

  2. Only sevara - I don't recall anything else (sorry, I don't have it with me at work)

  3. Phil Goode1:23 PM

    It's not clear to me why this is a question about the 16th of Av and not the 17th.
    Since in our calendar Av has 30 days it turns out that the 16th of Av is 15 days before the end of the month. And so any planting done on the 16th is 14+ days before the end of the month.


  4. What's the origin of miktzas ha-yom k'kulo? I know that it's "derived" from a ma'aseh regarding shmu'ah rechoka (either with Rabban Gamliel or Rabbi Chiya), but I don't know if there's any place from where the concept is more directly derived.

  5. Phil,
    Sorry ny calculation was a bit off. You need 30 days + 14. Elul is chaseir=29+another 15 in Av, one day of which you can say miktzas hayom k'kulo for. See Rambam Ma'aser Sheni 9:8-11.

    I need to look into it some more.

  6. Anonymous7:52 AM

    Had the taanaim had the proper means of observing how long a plant takes to develop there would be no dispute.

    So how long does it take?

  7. Anonymous,
    I discussed once before the issue of making a machlokes in metziyus; b'pashtus the issue is not one of proper observation but of defining what we mean by the abstract construction called "developed" as applied to a plant.
    See Shabbos 85a where the gemara asks how the Chachamim had such knowledge of botany and answers that they consuled the experts in the field [no pun intended].