Can plants encourage each other?

[Dante1709]

I've also heard of companion planting ; usually it's done with herbs, fragrant flowers or vegetables. Certain plants are said to attract beneficial predators or repel pests that attack the other plant. I doubt this is true for orchids, but it's possible.

Multiple plants can ensure that a lot of a water is absorbed through the roots, and that it drains better than just a single plant. Maybe this is beneficial for the plants that like quick draining media?