sounds like it's vines- if you have the HOA getting cranky over trellises, they'll have a conniption if you planted a bamboo there (though it would serve them right)

bouganvilla's the classic choice for your clime- it's fast growing, dense, impossible to kill, attractive- and 'privacy' is assured, since it's got spurs that make wading into it unpleasant.

trumpet vine is another one- that grows REALLY fast- mine thinks nothing of putting on 30 feet in a season, and in a frost free zone, it's pretty much the sky's the limit.

Bougainvillea is like wisteria, it needs something STRONG. A flimsy little stick-in-the-ground trellis won't support it for long.

I would think you could grow palms, canna lilies, oleanders or roses trained as a standard, melaleuca, hibiscus or citrus. 2' is plenty of room to plant, particularly if you improve the soil or better yet, build a planting bed which will give an instant 6-12" of additional height.

chinacat and jkom,
Thanks for the suggestions. I would love to have a bougainvillea but without a good strong trellis, it probably wouldn't work. My mother has one but she has a built-in trellis (she has the same model house with the same annoying HOA behind it but her trellis was 'grandfathered in.' Hmmm...I see a lot of those grandfathered-in trellises in my neighborhood. Anyway, I've got some hibiscus already so I am going to encourage them to put on some good growth and I planted some flowering vines out there too. I will buy some wire or a few of those long bamboo stakes and just place them strategically around the patio.

If they won't allow a permanent structure, how about a temporary one. You could have a planting box with attached trellis and grow vines.

See below for the Lee Valley version, if you are handy you could make something similar. A series of three or four foot long by two foot wide, 18 to 24" deep boxes should do.

And, although the boxes and trellis are removable, you don't actually ever have to remove them ;)

Here is a link that might be useful: Raised bed with Trellis

Thanks for that link Judy. It looks like a possibility. Especially since it stands alone and does not need to lean on anything. I was also thinking of a few obelisks or those large trellises that you dig into the ground. Only thing with them is that they are often around 72" high (which I need) but then only 6" of it gets dug into the ground. That doesn't seem like it would be very stable. I still have time to figure something out since my vine plants are still pretty small. I may also put some large pots on high pedestal type stands.
Thanks again!

You could also consider large trellis stuck into 2 or 3 large containers (in a row). It would be stable if you use concrete or cement to anchor them in the containers. Imagine 2 or 3 large posts stuck in each container. The concrete is only set up to a few inches and does not fill up the container. Top portion of the container is filled with earth or compost for planting. Then you could join each post to each other with horizontal 1"x1" grids/squares (be creative). This is not a permanent structure. Your can move the containered trellis about in the patio to suit your needs.

Ianna,
I may try your idea, minus the cement part. Maybe I could put the pots in a line along where I need coverage, fill them with potting soil and then stick the trellises down into the soil in the pots. I would have to get it so that the pots are spaced so that the legs of the trellises are aligned with the pots. Or make something myself to fit. And if the pots are about 2' tall, that lets me get away with buying a shorter trellis that would also be more stable just being stuck into the dirt, without being cemented in. All these great ideas!

One other idea is a row of containered bamboo (seeing that you are from a z10). They will grow fast and tall giving you great privacy.

Hi Gardenia, I have a very similar situation, but I can use a trellis if I want to, just want some privacy, so I guess I´ll use corn (Zea mays), in less than six months you get a private wall of 6-7 feet tall, corn to eat and lots of mulch to my fruit trees. I´ll sow corn each 3 months and see how does it work.

Jerusalem Artichoke, also known as "Outhouse Flower" has been used to hide unsightly outhouses in my Province for many times my own lifespan. They can be invasive so if you can limit where they grow you will be happier with them but they grow to 8' easy in one summer and die back to the ground. They also give multiple sunflowers from each plant and another bonus is that the tubers are edible. I have no idea if they would work well in your climate but perhaps even some type of tall grasses would work. Bon chance.

Balljoint,
Thanks for the reply. I had a hunch you must like working on cars...
Unfortunately I have to stay away from any invasive species since I have a small area to start with and anything I plant will be right next to my patio. I grabbed some clippings from my neighbor's rubber tree which she had just drastically pruned (I think Ficus elastica) and was going to try them but then I read that their roots can be destructive to the house/patio. That is a real bummer because they grow very fast and full and are pretty and would have given tons of privacy. They also require little care and are hardy. I might look into banana trees or the rubber tree in a pot.
Mercie beaucoups (hope I spelled that right!) Thank you.