I'd recommend against a pepper tree, even though I agree they're very pretty and they grow extremely fast, since in Southern California apparently they are considered invasive (see the link below).

Oaks would be an excellent choice, actually. Drought tolerant trees tend to have deep root systems that don't threaten things like driveways. Oaks don't grow particularly fast in general, though. The fastest is the coast live oak (quercus agrifolia), but I'd be nervous it might get sudden oak death one day. How about Engelmann oak (quercus engelmanii)? It's a lovely Southern California native.

If you want faster, how about Catalina Ironwood (lyonothamnus floribunda)? It has that shreddy bark like the pepper tree, grows very fast to 35-50 ft, and won't require any supplemental water unless you're fairly far inland.

Or if you really like the twisty gnarly thing, maybe Australian Tea Tree (leptospermum laevigatum)? I saw a great mature specimen at this park in Santa Barbara, if size isn't an issue this might be a great choice...also extremely drought tolerant.

Here is a link that might be useful: Invasive trees of Southern California

I've been researching your suggestions. There are so many choices ...

I like the Engelmann. It's native to this part of California which is a plus. Leaves aren't usually spiny it looks like. I really don't like the spiny leaves on many of the California oaks.

I was born in Minnesota, which is why I like the Valley Oak. The leaves look like "Oak" leaves to me. It's also a very fast grower for an Oak. Sadly the more I read about them, the less likely it seems one would do well long term.

The tree needs to be pretty large to shade the house, so the bigger the better. I'd love a 50-70 foot oak out front by the time I retire, which is at least 30 years away.

I still haven't counted out the California Pepper Tree (at least the Schinus Molle which seems to be less invasive). There are so many around here, that I was surprised to learn they aren't native. It should be called the Freeway Pepper Tree, there must be hundreds of miles of freeways and highways lined with the things.

The ironwood is interesting. I think I know where at least a few are planted, so I'll take a closer look.

Eric

Why do you think a valley oak won't work? Calflora seems to think that they've seen it in at least one site in Orange County (see link).

Here is a link that might be useful: Quercus lobata distribution

Interesting, that's great news. My main concern was a good deep water source.

I'm glad you posted that link, it's the first time I've run across that site.

Thanks

Eric

Eric, I am growing a valley oak in my front yard. It was 2" tall 7 years ago. Now it is pushing 12-15'. It is still skinny, but they are faster growing than most people think. Also, in my area (San Jose), I see them not only in the Santa Clara Valley floor (what's left of our great oak savannah) but also on the ridge tops of the eastern foothills up to 2000 ft or more. According to the Jepson Manual they can grow up to 5000' elevation. I have seen 20 year old trees at Hidden Villa that were about 15-20 feet, nicely filled out. Lots of acorns every other year. I just love the idea that it will live for 500 years if given the chance.

I'm with you on the Oak tree. We were lucky enough to inherit several mature specimens when we moved to this property, they are my favorite features of the garden. However, when it came to choosing a shade tree for the patio area I eventually settled on a Chinese Elm. It is relatively fast growing, needs little water, and does not have a damaging root system. Moreover, it adds an element of light and movement that a 'heavier' tree just doesn't give. It is more graceful with every year. In a few weeks it will be bursting with new growth, but even in the middle of winter the gorgeous mottled bark adds beauty to the garden.

Good luck with your selection.

Provence

I second a Chinese Elm. Resistant to Dutch Elm Disease and its weeping leaves look great in the summer. It is a fast grower as well. In winter it will also let in more sun as it will lose most of its leaves.

Along with the great suggestions here, I thought I would post a link to a list of trees native to Orange Co.

Good luck with whatever you choose! :)

Brenda

Here is a link that might be useful: CNPLX

Not usually listed as a shade tree because it has nuts, but it is also a wonderful shade tree. Macadamia. and it will thrive in your area. If you are a a couple miles or more inland, which it sounds like you are, I would recomend the variety Beaumont. Ohhh my they are a tasty treat too!

I am considering planting a Valley Oak. It's my favourite oak and seems to be a fast grower.

q lobata is probably the biggest native tree for warm flat dry clay. they tend to spread. i don't think one would reach 70 ft tall. the leaves take a while to all fall off, so you'll do multiple sweepings if leaves bother you (gutters).
[had a bizarrely huge crop of many oak acorns fall 2007, and i suspect the squirrels planted more than they could eat later. so I expect lots of seedlings (unless perhaps we get a horribly hot summer). ]

sycamore, Platanus racemosa, gets tall when along creeks, but no one seems to plant it so maybe it drops large branches or has other offensive behavior.
Acer macrophyllum, Bigleaf Maple seems to like more coastal/semi coastal, and be near creeks (very woodsy). I don't think it would reach 70 ft tall. but... http://www.na.fs.fed.us/Spfo/pubs/silvics_manual/volume_2/acer/macrophyllum.htm

the hybrid walnut rootstocks get huge, but are only half native :-) (and not at all native to socal) IIRC, they have no fruit or very rare fruit.

giant sequoia, isn't native to OC, but in southern sierras. doesn't like flat clay. tall and tall in proportion. seem slow. my impressions, but... http://en.wikipedia.org/wiki/Sequoiadendron#Europe
"one young tree in Italy reached 22 m (72.18 ft) tall and 88 cm (2.89 ft) trunk diameter in 17 years (Mitchell, 1972)"

santa lucia fir is nice looking. i think is very slow. might not tolerate warm clay.

cedrus spp

Araucaria (classic santa cruz monster tree) big cones, yep...

some pines, but cones or clay may be problems.

yeah, Macadamias are very nice looking trees. AFAIK need water to grow fast (or half fast), otherwise tough. (seem wide not tall, though)

castanea sativa (i think they're slow. tend to look gawky when younger. begin flowering while still small. nice green leaves)

Corylus colurna (I suspect slow, and a bit brillo looking in leafless season)

i had a question for those suggesting chinese elm. apparently there are 2 different trees that go by this name. may i ask which you are talking about? i was intrigued by your descriptions, but weren't sure which ones to research. there's ulmus parvifolia: http://en.wikipedia.org/wiki/Ulmus_parvifolia
and celtis sinensis: http://en.wikipedia.org/wiki/Celtis_sinensis
thanks!

I don't know what the others meant, but I would have meant Ulmus parvifolia. I have also heard it called Siberian Elm.
Renee

A camphor tree can be very special, but should not be planted near sidewalks or buildings because the roots can take up a lot of space, and protrude above the soil. The leaves have a pleasant aromatic smell, especially when crushed.

You might also consider an Alamo cottonwood, it is native to parts of California and the Southwest. If anyone absolutely needs a small tree, Mexican Elderberry can be an option. See this elegant Elderberry tree here.

You might consider fruit trees as well. Fig, of course, is very hardy and drought tolerant. Citrus does well where you live, but does need to be watered once a week in the summer. Mulberry has beautiful shade foliage, but is also very messy because of all the little fruits. There's not enough room to write about it here but it would be important to do research about the different mulberry varieties before choosing to buy one (for example, the fruitless males can have pollen and allergy issues).