@lovinglyjenoWell, plants are automatically watered when it rains. Once plants are watered, it takes a few days at least before they get dry enough to need watering again. The weather systems are more or less random. If it rained at least once every 3 days or so like clockwork, your plants might never need watering.
It's rare but no reason it shouldn't happen.
I know those things can be changed with mods, heck, I've done it myself. It's simplicity itself to turn off weeds and bugs for all plants.
If it's not rain, I'd say it's a mod. Have you tried removing all your mods?