More on strawberries that began in detached platforms transplanted into the ground
The obligation of terumot and ma'aserot for plants in perforated pots transplanted in the ground.
The Mishnah states (Ma'aserot 5:2): " If onions take root in an upper story they become clean from any impurity. If some debris fell upon them and they are uncovered, they are regarded as though they were planted in the field."
This ruling is echoed by Rambam (Hilchot Ma'aser 1:11):
When onions [stored in a home] grew roots next to each other, even if they grew roots in the earth of a loft, they are exempt from tithes. If a landslide covered them, and they are thus open [to the skies], it is as if they have been planted in the field and one is obligated to tithe them.
It seems that according to Rambam, crops growing on detached platforms are considered connected to the ground in the context of food impurity, thus deeming them pure even if they come into contact with impure foods. However, Chazal obligate crops growing in lofts in ma'aserot, as stated by Rambam (ibid., 1:10). In the specific case of onions, though, they are exempt from ma'aserot when growing on detached platforms. Perhaps this is because the subject in question is a vegetable, as mentioned by Mahari Kurkus (on Rambam, Hilchot Ma'aser 1:10), that perhaps the Yerushalmi's exemption for crops growing in lofts on detached platforms pertained to seeds, and what Rambam obligated derabanan in ma'aserot concerns trees, not seeds. According to this explanation, vegetables that grew on detached platforms are exempt from ma'aserot, but if the roof falls, the area is considered like a regular field, and thus the vegetables would be obligated in ma'aserot. Or Sameach (on Rambam, Hilchot Ma'aser 1:11) writes that the exemption would apply for a different reason:
And from the words of our master (i.e. Rambam) it seems that they are exempt from ma'aser since they are in a loft, and are considered planted indoors, which was exempted from [ma'aser] by the Torah but obligated only derabanan. It is for this reason that the Sages did not obligate them in this case, since one is not interested in them taking root.
Subsequently, if a landslide fell on them and they are exposed [to the sky], they would be considered planted in a field and therefore obligated, and this is a simple matter. See also the explanations of the Gra (YD) §294.
Or Sameach argues that the exemption for onions growing in a loft is due to the owner not wanting them to take root. However, according to all opinions, if the roof of the house caves in, the loft would be considered like the field and the exposed leaves would be obligated in both shemitah and ma'aserot. We can learn from here that removal from a place of exemption from ma'aserot (a loft) to a place of obligation (when the roof falls) obligates the exposed leaves, and therefore the strawberries here are obligated in ma'aserot. It seems that this removal must be before the vegetable reaches a third of its growth or onat hama'aser (tithing season). We learn this from Rambam's ruling (Hilchot Terumot 5:15) regarding a crop growing in an unperforated pot that was moved to a perforated one. There, Rambam requires the crop to have reached a third of its growth before the time of removal, and thus would be obligated after its transplant. In his words:
A flowerpot with a hole is considered as [connected] to the earth. How large must the hole be [for this law to apply]? Large enough for a small root to pass through it. This is smaller than an olive.
[The following rules apply when a person] planted grain in a flowerpot that did not have a hole and it reached a third of its maturity. Afterwards, he perforated [the flowerpot] and the grain completed [its growth] while [the flowerpot] was perforated. It is, [nevertheless,] considered as if it grew in [a flowerpot] without a hole. [This ruling changes] only when [the flowerpot] was perforated before [the grain] reached a third of its maturity.
In conclusion
Strawberries that were transferred before onat hama'aserot are certainly obligated in ma'aserot (with a blessing). It is also worth noting that the strawberries we were asked about were grown for domestic purposes, initially in a tunnel and not in a greenhouse (which is considered like a house for all purposes). It seems that a tunnel that is not at least 1 m high is not considered like a house, and therefore the crop would be obligated in ma'aserot. While part of it was in detached from the ground and part was attached, so in practice, one should separate only from the same batch to exempt that batch, and not from one batch to exempt another batch.
