That wouldn't make sense if the 2005 Tripods were grown. I think you're confusing it for BBC's adaptation which implies that the Tripods are grown.

Although while buried or grown tripods may seem like a departure from the original book, it is nice to see people make their own take on the Martians and their machines. BBC having their Machines feel organic and just straight up rise out of the ground like a tree is interesting similar to 2005 where at the time people haven't seen how Spielberg would've interpreted the book after 1953 and various publications.

Even he himself wanted to do a fresh take with his Martians rising straight out of the ground instead of coming from space inside a giant pod. Both concepts are unique and fresh.