Why are you planting them in containers? Most lilies can grow fine in zone 8. I would plant them in the garden in a sunny, well draining area.

Make sure they don't get water-logged and keep them OUTSIDE, the bulbs need the 'sleep'. I'm just north of you in Richmond, B.C. and I keep a fair number of year-round potted lilies, they do just fine, but, as you correctly observed, don't keep them with wet feet.

Pieter

Thanks, you two, for the follow-up. My bulbs are in containers because I've just built a new house (which if you are thoughtful you will remind me never to do again) and only now is the garden hardscape going in. In truth I should have waited to buy my lilies but did enjoy them last summer, that's for sure. Pursuant to your counsel, Pietertje, I'll move the numerous BIG pots outside then, but under cover lest they get too much rain. Thanks much.

I'm SE of Seattle & have kept lilies in large (@ least 12" diameter & depth) pots for many years. That way I could increase drainage for them to winter over better. Tiger lilies are in the smallest containers kept far away from the other lilies. My larger pots are >18" with oriental in one & an asiatic in another.

I fertilize them with composted manure in the spring that also works as a mulch. I water 1x a week during out summer drought season. I cut them back in the fall once the stems are brown. That's all I do for them.

This year I planted cuttings of spotted dead nettles in them along with winter sown annuals, so hopefully the lilies will do okay with perennials. The look was spectacular & I didn't have to tuck the pots in the flower border to hide the bare legs. In the early years I would add pansies, marigolds, lobelia, or petunia combos in them, but the lilies almost fill the pots now.