Defining the Melakha of Zorei’a
The first of the 39 melakhot of Shabbat is the act of planting/sowing, zorei’a. The gemara in Shabbat (73b) lists several derivatives of planting and catalogues them as part of this prohibition. Rashi claims that planting seeds of trees (notei’a) is equivalent to seeding vegetables; each is considered an av melakha. In contrast, Rabbeinu Chananel claims that planting a tree is considerably different than sowing vegetables; the former is considered an av melakha, while the latter is only considered a tolada.
Why should planting a tree be deemed less of a Shabbat violation than seeding vegetables? Indeed, some maintain that Rabbeinu Chananel was referring to planting saplings. That type of tree planting would clearly be less creative than – and therefore inferior to – actual seeding of vegetables. In the latter instance, the seed dissolves and a completely new product emerges – the growing vegetable. By contrast, when a sapling is planted, no (entirely) new object emerges; the original sapling simply grows larger. This augmentation is not completely creative, and therefore might not be sufficient to qualify as classic zorei’a, as Shabbat prohibitions are typically measured by their degree of creativity.
However, many claim that Rabbeinu Chananel should be read literally. His distinction between planting trees and seeding vegetables applies even to actual planting of seeds for trees. What possible difference between the two would explain the inferiority of planting trees?
This question may reflect a broader and essential question about the nature of the prohibition of zorei'a. We typically associate this activity with embedding a seed in the ground and enabling that seed to take root and sprout produce. From this perspective, there indeed appears to be little difference between the rooting process of a tree and the rooting process of a vegetable. However, this definition raises an interesting conundrum. Even if one were to plant a seed on Shabbat, the rooting process would not occur on Shabbat itself; the actual rooting would take place only after several days have elapsed. Shabbat activities with time-delayed results are usually only forbidden if the results also occur on Shabbat. For example, baking is only forbidden if the baked item reaches minimal baking levels on Shabbat proper. If, after placing food in an oven, one were to remove the food, no prohibition would entail (see Shabbat 4a). Since the rooting of seeds is delayed until after Shabbat, it is difficult to envision rooting per se as the essence of the prohibition.
Several Acharonim (Minchat Chinukh, Iglei Tal, and Ohr Samei'ach) debate this issue. Many concur that planting is different from other prohibitions, and the prohibition is violated even without ultimate rooting. Once the process is launched, the prohibition is violated even if rooting never occurs! Even if the seed were subsequently removed, the prohibition has been committed. The very act of placing a seed in a location that typically allows germination violates the issur. This renders the melakha of zorei'a unique; even though no transformation has occurred, the melakha has been violated. This would distinguish zorei'a from typical violations of Shabbat, which normally exhibit some transformation (such as cooked or baked food).
Alternatively, some suggest a completely different definition for zorei'a. In this view, rooting the seed and launching germination is not the essence of the prohibition. Instead, the prohibition consists of "nutrifying" the emerging plant. By placing a seed in a ground in contact with nutrients, a melakha has been violated. Since the nutrition begins immediately on Shabbat, zorei'a takes place completely on Shabbat and follows normal melakha parameters.
Thus, zorei'a can be defined in two distinct fashions. It may entail embedding a seed in the ground and causing it to be rooted and connected to the ground. Even if that rooting doesn’t ultimately occur on Shabbat, the activity that typically causes that rooting is inherently forbidden. Alternatively, the embedding is not as significant as the provision of nutrients, which inevitably begins immediately.
This question about the nature of zorei'a may be the basis for an interesting machloket about relocating a potted plant on Shabbat. The gemara (Shabbat 81) discusses a pot originally positioned on stilts that is currently relocated to the ground. The simple reading of the gemara indicates that zorei'a is violated on a de-oraita level. This appears to be the reading of the Rambam. Rashi and Tosafot, however, disagree, claiming that Biblical zorei'a has not been violated. Perhaps they disagree about the nature of zorei'a. In this instance, the potted plant has not been embedded or inserted into the land in this case, but the nutrition factor has been augmented by situating the plant closer to the ground. If zorei'a demands bonding with land, no Biblical violation has occurred; if it is defined as enabling nutrition, perhaps the issur has been violated.
This scenario invites a broader question. Would planting in an atzitz nakuv (a potted urn with a hole in the underbelly) constitute a violation of zeria? This type of vessel enables nutrition through the bottom hole. If zorei'a is defined as provision of nutrition, this type of planting should be forbidden. However, the seed has not been embedded in the land. Thus, if attachment to land is the core of zorei'a, no violation entails.
Returning to the original question of whether planting seeds of trees should be considered an av melakha alongside zorei'a, perhaps the question about the essence of zorei'a influences this categorization scheme. If zorei'a is defined as provision of nutrition, there is little reason to differentiate between planting seeds of vegetables and those of trees. In each instance, the produce will be nourished by the ground, and planting the seed initiates this process. However, if the melakha is defined as creating attachment between produce and land, a tree may yield a very different and looser form of attachment. By planting a vegetable seed, a person embeds a seed, which yields produce attached to the ground. By contrast, planting a seed of a tree yields a tree upon which produce is attached. Since the attachment is not directly to land but to tree, it cannot be qualified as a parallel av to the prototype of zorei'a.