I have a very large cherry that fits that poc

trickyputt what kind of cherry? Could you share a photo?

Immediately thought of California Buckeye. Great branch structure, gorgeous flowers in spring and deciduous. I'm more used to seeing them as a spreading large shrub but they can grow as single trunked small trees as well. Without added water it might go dormant earlier than you'd like too.

Since it's a native unsure if a large specimen could be found but they aren't slow growers.

Jean Thank you for that great advice. That all makes good sense.

Kathy Yata Just looked that up and love how the tree loses its leaves in the summer and grows them back in the winter. How very unique! The pods look very nice too. I can't find many pictures of single trunked California buckeyes or a good progression of what they might look like through the seasons. If I understand correctly, leaves in winter, leaves + flowers in the spring and into summer, lose of leaves and flowers in summer, grows pods in the fall, regrows leaves in the winter - is that right?

How tall do they normally get? Most of the multi trunked ones in google images look like they have low canopies. Ideally the canopies would start at the 8 or 10 height of a 20 foot tree at maturity so that we could sit or stand underneath on a slightly raised deck (1 foot raised).

20 ft. is a quite small tree and not a medium sized one. And all trees except certain desert species are shallow rooted. Whether they also have some deeper penetrating anchorage roots or not. Expect roots from just below the surface to as far down as a particular kind of tree goes anywhere you plant a tree.

California buckeye is poisonous to bees, which then walk around all over beneath the tree, drops large fruits and grows bigger than 20 ft. - even as far north as Seattle, where one was 44 ft. tall with an average crown spread of 52 ft. in about 2005.

California redbud might be more in scale with what you have in mind.

Embothrium Thank you. I definitely don't want a tree poisonous to bees.

I will look into the California redbud now.

Arbutus unedo or Arbutus 'Marina' both have year round interest, flowers, nice bark, relatively drought tolerant and tough, 'Marina' is faster growing than unedo. The only problem is the fruit when you build your deck. But the fruit isn't very messy in my experience. There are rarely perfect trees for any given situation.

kentc Thank you. I don't mind fruit or flower debris. I looked at the single trunked varieties and wondered if they looked a little out of place on our hillside? Our neighbor across the street has a multi branch arbutus in their front yard and it is lovely, very reminiscent of the manzanitas local to our area but the single branched version looks more like a sidewalk tree than for our location. Love this tree, however.

Ideally the canopies would start at the 8 or 10 height of a 20 foot tree at maturity so that we could sit or stand underneath on a slightly raised deck (1 foot raised).

What you have described here is in fact nearly the same as a tree pruned to function as a street tree, with a crown that is below power line level on top but high enough beneath for vehicles to pass by without hitting it (trucks need an even higher 14 ft. clearance). Having half the height of a 20 ft. tree be bare trunks is a pretty extreme situation, one unlikely to be seen most of the time without a lot of pruning. Also keep in mind that most trees take many years to develop enough size to produce a pool of shade large enough to cover all of a hot weather seating area. Apart from something like a windmill palm - which looks tropical, of course, and will always produce a tiny shadow - maybe you could get a silk tree to work. If the one you planted happened to be small growing on your site, otherwise these are yet another that can get a lot bigger than you want. What you are most likely to need is a tree like this that naturally produces an markedly umbrella-like shape.

There's a garden and patio tree table in the plant selection chapter of the Sunset Western Garden Book, you might want to look at that.

Crepes and Birches can be kept at your height

That is a big cherry.

grows to about 20 feet

That's a shrub size, not a tree size. If you are adjacent to natural land then a native appropriate to your area such as one of the Manzanitas (Arctostaphylos) or a native scrub oak such as Quercus berberidifolia.

Maybe a toyon could be pruned as a single trunk tree. Arbutus could be a good choice as well.

pics!