Analyzing the Roots: Hydroponics and Halacha
According to some accounts, the Hanging Gardens of Babylon were hydroponically-grown. The gardens hung strikingly from palace terraces and were considered one of the Seven Wonders of the World. The gardens were supposedly constructed by Nevuchadnetzar around 600 BCE in present-day Iraq, about 30 miles south of Baghdad.1 However, there is a lively discussion among historians as to who built the gardens, how they were planted, and indeed whether these gardens existed at all. The Talmud (Avoda Zara 38b) itself discusses the hydroponic sprouting of seeds, in what seems to have been a fairly common practice.
More recently, in the 1930's, Dr. William Gericke of the University of California conducted research with hydroponics. He coined the term "hydroponics", derived from the Greek words, hydro (water) and ponos (labor), or "water-working." Put simply, it means growing plants in a nutrient solution without soil. The science of hydroponics proved that soil is merely the holder of the nutrients, as well as the place where the plant roots traditionally live and a base of support for the plant structure. Soil isn’t required for plant growth; the elements, minerals and nutrients that soil contains such as carbon, nitrogen, phosphorus, potassium and magnesium can be supplied in liquid solutions. Plants are supported by porous material, such as sand, gravel, foam or glass wool, that acts as a wick in relaying the nutrient solution from its source to the roots.
In 1945, the United States Air Force built one of the first large hydroponic farms on Ascension Island, a barren island in the South Atlantic, followed by additional farms on Iwo Jima and Okinawa in the Pacific. These hydroponic farms helped to supply fresh vegetables to troops stationed in these areas. Over the past few decades, researchers in Israel have been at the forefront of hydroponic study.2
Presently, the most common hydroponic crop grown in the United States is tomatoes followed by cucumbers, lettuce, herbs, and peppers. In addition, every day many hydroponic vegetables are brought in from Canada, Mexico and Europe.
Now let’s discuss the various halachos which are applicable to the AeroGarden, and to hydroponics in general.
In addition to romaine and other types of lettuce, one can grow herbs such as cilantro, dill, and parsley. Herbs are especially prone to infestation, are difficult to check, and are not widely available to the kosher consumer as ‘certified insect-free’. The kit is helpful in controlling infestation for these varieties.
Hydroponically-grown vegetables (lettuce, herbs, etc.) sold commercially without kosher certification should be thoroughly checked since they grow under conditions unknown to the consumer.
The vegetables may not be harvested on Shabbos or Yom Tov due to the prohibition of kotzer, reaping.9 On Chol Hamoed, they may be harvested for Chol Hamoed or Yom Tov use. Although the AeroGarden lights go on and off during Shabbos, this is permitted since the system is automated without further input.10
On a related note, if the seeds in the kits were to come from Eretz Yisroel, the seeds would not be subject to the laws of ma’asros or Shmitta. These seeds are not edible seeds, and the Mishnah in Ma’asros 5:8 states that non-edible seeds are not subject to ma’asros or Shmitta.13 In any event, Star-K has determined that the AeroGarden seeds are not from Eretz Yisroel.
From early history to modern times, hydroponics has offered an alternative to earth-grown produce. It is yet another way to appreciate the bountiful world Hashem has bestowed upon us.18
1. This would be around the time he destroyed the Beis Hamikdash. It is said that the gardens were built to cheer up his wife – a native of a lush region full of vegetation, who found the dry Babylonian scenery dispiriting.
2. In 1982, Dr. Hillel Sofer, senior researcher at the Volcani Institute at Ein Gedi, developed the aero-hydroponic method, which increases oxygen to the plant roots by suspending the roots in air. The AeroGarden uses this methodology.
3. Rav Ovadia Yosef (Yechaveh Da'as 6:12), Rav Chanoch Zundel Grossberg, (Siddur Minchas Yerushalayim p. 334), Rav Eliyahu Falk (Machazeh Eliyahu siman 28). All cite the Chaye Adam 51:17, who discusses vegetables grown in soil in a flowerpot (sh’aino na’kuv, without holes on the bottom). Chaye Adam rules that the brocha is Shehakol, since it is not nourished by the soil in the ground. Although some disagree with the Chaye Adam on that point, his ruling provides strong support for reciting Shehakol on vegetables grown in water, which is even further distinguished from earth-grown vegetables.
4. There are opinions (Rav Shmuel Vozner Sheivet HaLevi 1:205, Rav Moshe Shternbuch Teshuvos V’hanhagos 2:149) that the proper brocha on hydroponic vegetables is Hoadama,asHoadama is recited over any vegetable which normally grows from the ground. (Rav Shternbuch writes that Chaye Adam only referred to Hamotzi, which could not be recited on bread made from wheat grown in a flowerpot. However, this argument is difficult to support, as Chaye Adam refers specifically to Hoadama. Also, see Nishmas Adam 152:1 where the Chaye Adam explicitly links the two brochos.)
5. Yechaveh Da'as 6:12.
6. During Shemitta years, Alei Katif may be grown differently than in other years.
7. A test of the system in the Star-K offices produced lettuce which was insect-free.
8. Shulchan Aruch O.C. 336:11. See Minchas Chinuch 32 and Teshuvos Har Tzvi (Zeraim 2:31).
9. Shulchan Aruch O.C. 336:5, Shemiras Shabbos Kehilchasa 26:4, Machazeh Eliyahu 31.
10. Even Rav Moshe Feinstein (Igros Moshe OC 4:60), who disapproved of ‘Shabbos clocks’, still permitted their use for lighting.
11.Rav Yechiel Michel Tuchetzinski (Zeriah 3:4) and others cited in Mishpatei Aretz (Terumos 1:19). Teshuvos Har Tzvi (Zeraim 2:31), however, requires ma’asros. See also discussion in Derech Emunah (Terumos chap. 2, Beiur Halacha s.v. Ochel).
12. Yechaveh Da'as ( 6:12) citing Rav Yechiel Michel Tuchetzinski (Sefer Ha’Shmitta vol 2:pg 104),
13. The Rambam (Peirush Ha’mishnayos) writes, based on the Mishnah, that even if the seeds come from vegetables which themselves have been set aside as teruma, the plants which grow from these non-edible seeds are not teruma. We do not apply the rule of gidulei teruma teruma. See also Rashash.
14. Also see Pesachim 39a, ma matza gidulei karka af marror gidulei karka, implying that marror must be earth-grown. However, this may mean only that marror must be a type of food which normally grows from the earth. See Mikraei Kodesh Pesach 2:12.
15. Mishnah Brura 473:55, Aruch Hashulchan 473:18.
16. Although horseradish may warrant a brocha of Shehakol when eaten raw and yet it is used for marror, on Pesach night its brocha is likely Hoadama since it is eaten to fulfill the halachic requirement (see Beiur Halacha 575:2). However, the brocha on hydroponic lettuce remains Shehakol, even on Pesach night.
17. Shulchan Aruch Y.D. 142:11. See also Shach Y.D. 60:1 quoting Tosafos (Avodah Zara 59a) regarding plants grown on issur achilah..
18. There are other halachic areas where it is relevant to discuss whether hydroponics is gidulei karka -- leaving peah; tochen and imur on Shabbos; buying food with ma’aser sheni money; a poel eating from produce; and s’chach. We plan to cover these issues in the future.