Are you using them, or if not, do you think you will? What for? I mean, they're sort of nice when you realize while redesigning your farm in winter that you need Starfruit for Junimo Huts, but otherwise, the fact that they don't seem to get watered by sprinklers (at least indoors) makes me think I probably won't be using them much afterwards. Unless that gets changed, of course. Maybe I just don't yet get how I should be using them.
They can be put in the Garden House (I believe), which does have sprinklers, in places you would otherwise only be able to put trees before. The pots don't take ancient fruit seeds, but this just means you can grow Starfruit year round. Another useful feature is that they can be put on grass that cannot be tilled, such as in the Forest Farm Map, so you can increase the amount of space you have to normally farm. Provided of course we can put sprinklers on un-tillable grass. But otherwise, they are useful for having to grow something out of season that you don't have at present. Or they would be if getting the seeds for such was possible in the middle of an off-season. So still better to have the needed fruits on hand before any quest pops up. It's not like they rot in this game.
That's where I have mine, and I have sprinklers that would reach them, but they aren't affected. I have to manually water them, so it sort of negates any benefit of being able to grow plants in that area for me.
That's weird, it's either a glitch or the devs really wanted gardening pots to be under-powered. Do they even get watered by sprinklers outside?
I think they're mainly going to be decorative items, so for instance if you plant a few of them you can always have a coffee first thing every morning before you leave your house. Actually, for added realism, probably need at least ten plants......
As with most sandbox games, there isn't really a 'should' when it comes to using them. CA has given the players a new creative tool to play with. Aside from limiting it to not allowing Ancient Fruit, seems like you could go nuts with them. I saw one person on Youtube set up a mini-greenhouse in their house using the nursery space. Start a grape arbor indoors. Sunflowers in your kitchen. It seems like they'd be of only minor utility for extra profit, but as a creative/decorative item, they're rather interesting.
So far I have one cactus growing in the pot Evelyn gave me, but I may once winter gets here use them in sheds. Is there a way to use sprinklers to water them or must I do that by hand?
You have to do it by hand. Sprinklers don't work in sheds, from what I've read, and like I said, they don't work on the garden pots in the greenhouse, either. They might not work on them at all.
Actually yah, I did want to confirm whether the sprinklers outside worked on gardening pots. This would make gardening pots useful on grass-heavy maps like the Forest Map. But again, it seems that sprinklers don't work on gardening pots anywhere. Edit: According to the wiki, sprinklers do not work on gardening pots at all. https://stardewvalleywiki.com/Garden_Pot
Hopefully they'll at least consider changing this. So far, the sunflower in the kitchen idea sounds great to me (thank you, @Lilliput), but that's about it.
Growing whatever flower or produce your spouse likes also seems an excellent use for these pots, that way you can keep their heart-level up. But yah, I hope they change it too. I would rather the pots had more versatility.