As a novice to gardening, I suspect that my potted plants on the patio are
victims of poor drainage I.e. the leaves have gone yellow from the ground
upwards after an initial spurt of growth. I understand that to cure this, one
should put broken terra cotta in the bottom of the pots (or something like
this) - anything else I need to do?

And is it worth saving the plants somehow (Russian Vine, Jasmine) or better
to start again? Oddly, the Ivy seems to be fine.