Another scumming method is bringing a Banshee to the Animated Forest. In this tactic you kill the trees using the Banshee and pick up the dropped items. The banshee kills the trees really effectively, and because it's not the player who's killing them, they don't become more powerful. And because the level generates infinite trees, you get infinite item drops. The only problem is that the Banshee gains experience really fast and is a threat to the PC, but that can be worked around by having enough speed or locking it inside doors (made by wands of door creation).

Just make plants immune to her wail. They don't have ears, after all.