You described my garden sun and shade pretty well. Not much will bloom in the winter without sun. Primroses and Snapdragons are blooming now, but they don't do well in the full sun of the summer. I have some Alstroemerias and day lilies blooming but not as good as they should, without sun. Camellias are budded and ready to bloom. Helleborous are budding and will bloom soon. Osteospermum have been blooming for months and still look good. Hope this gives you some ideas. Al

I have the same problem. I grew a privet as a small tree to solve the problem- now the area gets light shade in the summer. I grow ferns, calla lilies, and clivias there.
Renee

Our backyard faces north. It gets summer sun until about 1pm, and bright shade all winter (except for a speckle of early-morning sunlight during sunrise). In spite of several hours of summer sun, I would not call it a place for "sun plants", but rather part sun or morning sun.

In this spot, we grow: Hydrangea, Columbine, Salvia regla, Plectranthus 'Mona Lavender', Eranthemum (shrub with turquoise-blue flowers), Clivia, and Liriope. Other plants that would like this spot include some Geraniums and Pelargoniums, some Salvias, some Mimulus. If a plant is labeled for "part sun" and can tolerate shade, it could go in this spot. Personally, I would not try plants that love "full hot sun", but my tolerance for failures and having to move things around is not very high. :-)

The Salvia regla was an experiment in this spot. I stuck a broken stem in the ground, it rooted, and grew into a beautiful specimen that reaches our roof line. It is spectacular in bloom (summer), and tolerates our heavy clay soil in bright winter shade. The foliage might be more dense in full sun but it has done well in this spot for several years.

Look for plants that like morning sun; it may take some experimentation to see what works and what doesn't, and you may be pleasantly surprised at how much you can grow there.

I thought of another one... Heuchera.

I know that some of the plants I suggested are taller than what you're looking for, but they may give you some ideas and inspiration. I'd dig around on sites like Plant Delights or Digging Dog Nursery, High Country Gardens.. (for examples... there are more) for plants that like part sun to shade, to get a sampling of such plants that match your criteria.

Jenn, thanks, but I think the first two posters nailed the problem. Can't grow partial shade plants in month after month of 8 hours/day of burning Southern California sun: they will just die. Got to have plants that love the sun, but can also be in heavy shade for 4 or 5 months. Hosenemesis: interesting suggestion. Maybe for the long term.

@Oona I wonder if you'll see this on such an old post! I'm in Perth Western Australia with a similar climate and have the same dilemma (south side of the wall here though!) I'd be interested to know what you have found successful?

Try daylilies. They'll grow in spring and summer. In winter they'll go dormant.