Using an aloe vera leaf to facilitate shoots taking root

Answer

The world of agriculture is constantly progressing and developing. To help various shoots take root in the ground, several growers have recently begun inserting the shoot into an aloe vera leaf and planting them together in the ground. Thanks to its fleshy leaves full of sap, the aloe leaf provides moisture and protection from fungus. Note that the intent is not to propagate the aloe vera leaf, rather to use it to aid the shoot in the process of striking roots.

Aloe vera is used primarily for cosmetic purposes, so it is halachically defined as a non-fruit-bearing tree, etz seraq. Like other such trees, it is forbidden to graft fruit-bearing trees onto it.

The Mishna in Kila'im (1:8) cites examples of connecting plants in different ways—seemingly unrelated to actual grafting:

"They may not plant a young fig shoot in sea squill so that is might provide shade for it. They may not insert a vine branch into a melon, in order that the latter might shoot its moisture into the former."

The Mishna describes two cases that seem to have different purposes: (1) planting a fig shoot into sea squill; (2) inserting a vine branch into a melon. Both acts are prohibited due to the prohibition of kila'im.

The explanations of the Rishonim here are that the very act of connecting two plants is prohibited, even though in doesn't actually produce a graft. This is also the understanding of the Yerushalmi: it is forbidden to insert a grapevine into a melon, since the plants receives nourishment from one another, even though they do not mesh into one another.

Nevertheless, many Acharonim maintain that in the case where it is impossible for one of the plants to produce foliage independently for the long-term, and it shrivels and dries up after several days, this is not a grafting prohibition.

For this reason, shoots should not be inserted into aloe vera leaves, since (1) the aloe vera plant is fleshy and can self-propagate, and (2) it contains a significant amount of sap from which that the grower wants the shoot to receive its nourishment. This method can only be used if one ascertains that the aloe vera leaf does not take root whatsoever or have the ability to do so on its own.