Children sims tend garden option showing?

@wexxam Thank you for your patience while I checked on this. 😊

So I did a brand new vanilla save, no mods whatsoever (except NRaas, I'm amazed at how quickly the game loaded up! 😃 ) and picked on the Bunch family in SV cause they have children. 😉

I then placed down some lettuce plants in their backyard and set the season to Winter, to make the plants go dormant. 👍🏻

Sure enough, when I sent little Ethan to "Tend the garden" it was greyed out like you said. 

See here:

So in conclusion, no this was not the result of having that "children can series" in your game, it is a common occurrance, built into the game, when the plants are dormant. Because really, who would tend dormant plants in real life in the winter because they ain't growing anything. Lol! 😉😆👍🏻 But I will say it's annoying to have weeds around your plants, and then they go dormant in the winter, and you can't send your sims to pluck up those dang things! 😬 (That was the thing in my modded game that threw me for a loop I mentioned earlier, but when I got to thinking about it...yeaaah. 😉 ) 

So no worries, your game is just fine. 😊 Enjoy playing!