When I try to plant it - it tells me the seed doesn't exist. Help?

It may be glitched.

The Gardens in general have been glitchy for a while. :(

Damn. I really wanted to plant it.

From what I can remember, the Magnificent Onion Pod has been glitched for a while now, probably a few months. :( Maybe put a thread in Problems and Bugs? :/ shrugs