A squib is a person from a wizarding family who can't use magic. ...It's a terrible thing to be. [There's a hint of sadness as he says this, but it goes away quickly enough.]

I don't know if they ever will. Once they've sprouted some more secure roots, I'm going to transfer them into pots and bring them inside where I can control how much noise gets out once their voices get stronger. But it's mostly just a theory right now... I don't know if the charms I put on the seeds will hold out long enough.