Separating terumot and ma'aserot from home hydroponically grown produce

Answer

Terumot and Ma'aserot

If the balcony is paved and also has a roof, or if it is actually inside the house, then it is possible to be lenient and not separate terumot and ma'aserot (though some are stringent).

[We are lenient because the plants are growing in unperforated pots indoors, in which case their obligation in terumot and ma'aserot presents a halachic doubt (safek). Furthermore, when planting in water (hydroponics), there is another doubt, and with double doubts (sefeik-sefeika) we are lenient.]

If, however, the balcony is uncovered and exposed to the sky, terumot and ma'aserot should be separated without a blessing.

Shemitah

If the balcony is paved and has a roof, it is permissible to plant there during the shemitah year (even if you add fertilizers to the water). If there is no roof, one should avoid planting (if you do not add fertilizers to the water and there is no soil or growing medium at all, some are lenient).

Orlah

One should be stringent and wait for the years of orlah before eating fruit. However, it is possible to consider the years in the nursery as part of the orlah count.

Neta Revay

It should be redeemed, and it seems it can also be done with a blessing.

Blessings

The accepted custom is to recite their regular blessing (either adamah or ha'eitz), not shehakol.

Kilayim

Ideally, one should be stringent and keep the proper distance between seeds of different types (1.5 tefachim or 12 cm).

Elaboration

The halachic authorities have debated the issue of growing plants hydroponically, mainly with regard to shemitah – whether it is forbidden as with cultivation in the ground—and regarding the prohibitions of Shabbat. From these issues, the discussions are derived regarding hydroponics concerning separating terumot and ma'aserot, kilayim, and the first blessing on vegetables grown hydroponically.

Rambam (Shabbat 8:2) and the Shulchan Aruch (OC 336:11) wrote that one who sows grains on Shabbat in water is liable due to sowing; it is implied that sowing in water is likened to sowing in the ground.

On the other hand, Rambam (Shemitah 1:6, citing the Yerushalmi 4:4) states that it is permitted to soak seeds in water during shemitah to sow them after the shemitah year. This implies that there is no prohibition of sowing in water during shemitah.

In the book Nechpah Bakesef (I, YD§5), Rabbi Yonah Navon (18thC) distinguishes between Shabbat and shemitah, stating that on Shabbat the prohibition is on the human act of sowing, whereas during shemitah, the commandment is to let the land rest, so the prohibition only applies to sowing in the ground. It follows, therefore, that there would be no prohibition during shemitah in hydroponic cultivation. However, he adds that if a little soil is added to the water, then it would be forbidden to sow in it during shemitah.
In all hydroponic systems, some fertilizers are added to the water (which substitute for soil nutrients). These fertilizers might be considered soil, making it akin to sowing in soil.

However, Har Tzvi (2:31) and the Chazon Ish (Mishpetei Eretz 1:19) understood Rambam's leniency regarding shemitah differently. Rambam permitted soaking seeds during shemitah only with the purpose of planting them after shemitah, meaning to soften them briefly in water, and then later to sow them in the ground. This action is permitted during shemitah (though forbidden on Shabbat) because it is not actual sowing but rather preparation for sowing. However, sowing in water for the purpose of initiating plant growth would be entirely forbidden during shemitah since this is the regular manner of cultivation.

In practice, there are three major opinions regarding hydroponic cultivation (outdoors) concerning shemitah and terumot and ma'aserot:

a. Har Tzvi, Rabbi Eliahu, Chazon Ish (according to the Har Tzvi's understanding), Shavet Halevi (1:1) – hydroponic cultivation is obligated just like cultivation in the ground.

b. Nechpah BaKesef, Rabbi Zilber (Az Nidberu 8:51), Rabbi Grossberg, and the Chazon Ish (according to Rabbi Zilber's understanding) - hydroponic cultivation is exempt, and obligated only if there is soil present (and there is a debate if fertilizers are considered soil).

c. Hydroponic cultivation is exempt, even if there is soil present.

It should be noted that most hydroponic systems are defined as non-perforated pots (atzitz she-eino nakuv) - thus, the obligation regarding them is only rabbinical and not biblical.

In practice - for outdoor hydroponic systems, defined as non-perforated pots, terumot and ma'aserot should be separated (without a blessing).

As for indoor hydroponic systems, it is possible to be lenient and not separate terumot and ma'aserot at all, even when fertilizers are added (Rabbi Yehuda Amichay, head of Torah VeHa'aretz Institute, ruled as such). Some posekim advise separating terumot and ma'aserot without a blessing (Mishpatei Eretz, Rabbi Eliahu).

Orlah

We have discussed orlah in hydroponic cultivation elsewhere. Scientifically, this is relatively rare, as most hydroponic cultivation today (as of 5784) is for vegetables, and there are hardly any trees grown hydroponically. In practice, Rabbi Yitzchak Yosef and Rabbi Yehuda Amichay wrote that the prohibition of orlah applies even to hydroponic cultivation.

Neta Revay

Indoors: without a blessing

Outdoors: There is a doubt whether to redeem the fruit with a blessing (Rabbi Yehuda HaLevy Amichay has not ruled definitively on this matter), So better without a blessing.

Kilei Zera'im

The Tosefta (Kilayim 1:4) states: "One who sows something that stimulates growth ... on a rock or on an aqueduct is exempt;" this is also written in the Yerushalmi (Kilayim 1:9). This implies that there is no prohibition of kilayim for hydroponic cultivation. Likewise, Rabbi Grossberg writes (Kerem Tziyon 14, p. 218) that there is no prohibition of kilayim for hydroponic cultivation without soil.

However, Har Tzvi (Zeraim 2:31) on the Tosefta adds that the exemption only applies where the plant cannot develop properly (sowing for destruction), such as sowing on a rock or gravel where the plant cannot develop properly. But if the plant can develop properly, then the kilayim prohibition still applies. This is also brought by Rabbi Kalman Kehana in the name of the Chazon Ish to be stringent (Halichot Sadeh 88, p. 23).

In practice, it is best to be stringent with kilei zera'im even with hydroponics and even when indoors, since they draw their nutrients from the same source due to their close proximity (Rabbi Yehuda Amichay).

Shemitah

For indoor hydroponic systems, it is permitted to sow during shemitah even if there is a little soil present. This was done in Kibbutz Chafetz Chayim under the guidance of the Chazon Ish (as quoted by Rabbi Kalman Kehana). However, the Chazon Ish prohibits sowing in outdoor hydroponic systems during shemitah.

Regarding practical halachah for hydroponic cultivation during shemitah, further discussion is necessary.

Blessings - I hope to expand on this in a subsequent article, be'ezrat Hashem.