certain spells and effects function differently against feyward trees:

a magical attack that deals cold damage slows a feyward tree (as the slow spell) for 3 rounds.

a magical attack that deals lightning damage breaks any slow effect on the feyward tree and heals 1 hit point for each 3 damage the attack would otherwise deal. If the amount of healing would cause the tree to exceed its full normal hp, it gains any excess as temporary hp. The tree gets no saving throw against lightning effects.

The feyward tree is immune to any spell or effect that would alter its form.

A feyward tree has advantage on saving throws against spells and other magical effects.

The feyward tree’s weapon attacks are magical.

Creatures within 15 feet of a feyward tree provoke opportunity attacks even if they take the Disengage action before leaving its reach.