Easy

Once the patch of grass agreed to move Lex informed Mary to summon the turtle. Other than the grasses' surprising cultivation level, another reason why the turtle never attempted to communicate with the patch itself was due to the fact that the grass had the perfect disguise. Its aura was completely untraceable and,albeit slowly, it could move wherever it wanted within the lawn.

There was just one final thing left to do, which was give it a name. After all, Lex couldn't go around calling it the patch of grass. A single, unnamed turtle was already annoying enough for Lex.

After a moment's consideration, he named the sentient grass Zen. There was no particular reason behind it, and Lex definitely did not consider giving the grass the last name Garden either.

With that done, Lex finally returned to the Recovery Pod and lay down just moments before losing consciousness. If all went according to plan, this would be the second last time this happened to him.