Planting spell, or the art of singing to plants, was the unofficial name given to the spells used by the elves to make plants grow and expand at a rapid pace.
Such spells were typically sung. Presumably, the different intonations and speeds used in the songs were what shaped the plants to look as the elves desired them. Non-elves could also learn to use planting spells, but since they took a lot of energy, only the strongest could, and only for small purposes.
Planting spells could be used to accelerate the growth of plants, or cause them to grow in new ways, forming new kinds of flowers or objects. Trees, being made of wood, could be shaped into myriad things. One unusual use was to compress the wood, making it eventually become as hard as steel, but very heavy.
Role in the booksEdit
The elves used planting spells to make almost everything in their domain - houses, buildings, canoes, ships and bows. The entire city of Ellesméra was created by planting spells.
In Brisingr, Eragon used a planting spell to make a flower grow, which he gave to Arya. This was one of the only serious compliments or favors she accepted without halting his advance.