pittisporum "taiba"....the dwarf mounding shrub that is light green, or maybe chartreuse is a better description of the foliage color. I may have misspelled the variety name.

These pittisporums need very little pruning to maintain their shape. Easy to grow in northern CA. Make nice mounds 1 to 2 feet tall. Spread nicely too.

You didn't mention what type of japanese maple. I'm assuming the weeping lace leaf varieties. It that's the case I don't plant anything under them but mulch. the reson for this is the require pruning and the best way is to lie on your back and prune from the bottom up and inside, resulting in a thin umbrella. That way you can see the trunk better even in summer. Just prune out the branches that are going to be superceded anyway by the natural overlapping growth of the branches.

If however, you are going to have upright Japanese Maples, you can plant almost anything that will grow in your area.
Here's what I did by my driveway,"{{gwi:452026}}"

Here's another shot of some maples in the garden.

Here is a link that might be useful: Maples in the garden

stunningly beautiful!

Hostas.

The pittosporum is likely P. tobira 'Wheeler's Dwarf'.

Just some old photos many folks here might have seen over the years of my garden. Got tons of perennials for free and grew some from seed until I incorporated conifers and Azaleas, ect.

Dax

Shade area that's still the same:
Acer palmatum 'Seiryu'
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Acer japonicum 'Acontifolium' a few years old (photo):
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'Seiryu' a few year old photo or thereabout:
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'Acontifolium' older photo yet (Full Sun):
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'Acontifolium' when perennials blooming still full sun:
{{gwi:1049467}}

Dax

Nice Dax! I like the full look of the A japonicum 'Acontifolium'. I was surprised how fast mine grew. It got too big to move before I knew it and now I have to prune to keep it out of the driveway so trucks can get by. It's as thin as a plate. lol