Quote Originally Posted by ToasterMan View Post
Why would they not allow you to cross bread seeds in these plots? That's ridiculous.
Probably because the gardens are a single object in the game, which contains multiple places to plant. The pots however are likely going to each be separate items and as such have no link to any other game items (so won't be aware of items placed next to them).

I'm also no botanist, but I'm pretty sure that to crossbreed plants they have to be touching, something that'd be a lot harder if they're in separate pots instead of planted next to each other in the same soil.