This is a discussion on Quarantine Plants within the Beginner Planted Aquarium forums, part of the Beginner Freshwater Aquarium category; -->
I received some free frogbit from someone who I really don't know.
Rather than just adding it to my main tank I thought I ...
I wouldn't worry about the snails, but the worms don't sound good. Normally I never quarantine plants, but this is a risk obviously; if they come from tanks with fish they can carry ich and other issues. As long as the QT has light over it, quarantining in this case might be wise.
Dipping plants in solutions of this or that is sometimes suggested, but I've never done this and wouldn't; if the solution is strong enough to kill parasites, snails or worms, it will likely harm the plants.