I'm starting to raid my vermicomposter for worms to put in my container plants.
Most of the big containers that had been outside, sitting directly on the ground, should have some in there already, but I did uppot and repot some before bringing them in, and some of the original worms may not have made it back into the same containers. And I have a bunch of smaller containers that I KNOW were filled with unpopulated fresh potting mix. (Those get baby worms
The resident worms are more likely to be night crawlers and earthworms that prefer to burrow around and aerate the soilmix and live near the bottom of the containers. And those containers have the clay-blended garden soil mixed in to keep them happy.
But these will be red wigglers from a fresh batch I bought at the end of the summer, so they may not be as helpful for aerating the soilmix, but they will do better in some of the small containers that were filled with ONLY commercial (peat and perlite + compost/organic fertilizer) potting mix.
They will get additional "food" since I'm constantly watering with UCG (used coffee grounds) and leftover beverages in the water, as well as mulching the surface of the container soil with used (herbal and regular) tea leaves from the teaball and dried/dead leaves (most of my plants experience some level of seasonal deciduous stage as well as drop leaves due to changed environment) clipped into confetti. They can also treat themselves to any dead roots due to over or underwatering.
Whatever kind they are, the worms will act as "slow-release fertilizers" producing daily worm casting to nourish the soil microbes and the plants