It seemed clear that all the outdoor basil were getting root bound. When I added water to the pot it didn’t take much to fill it up, and it didn’t stay wet for long.
We pulled each one out, loosed up (and tore off) the root layers that had formed on the outside, then replanted them. Prince, Ghost Fire, and Summer Sunshine all went into a big 8” x 23” planter, so they should have plenty of space and a decent amount of sunlight. Morty went into his own 6” pot.