Mark Anderson wrote:

Next year I need to rebuild the containers that hold the morning glories
and I was thinking of employing this hydroponics-lite technique by build
water reservoirs for the MG's roots to congregate as they start getting
big. I'm a little unclear as to what's going on with these MGs this
year and why roots soaking in water would do better. According to what
I read about hydroponics, I thought that roots also need oxygen too
which is why those systems pump water in and out of the root system. On
other trellises they're growing in very large pots where being root
bound shouldn't be a problem but they're going barren as well so I'm not
even sure if being root bound is the problem. Any insight would be
appreciated.

Maybe watering them so frequently is leaching all the nutrients out of
the potting soil? Or perhaps the soil in the small pot had more
nutrients to begin with, if it's fresher than the stuff in the large
pots that have been used for a few years? Are you using any sort of
fertilizer?