shrubs and trees never really stop growing ... many height estimates are at 10 years or so ...

so it will almost always becoming a maintenance issue ... involving pruning ... and at 20 odd feet... short of a cherry picker.. i dont know how you prune at that height but for with a checkbook ...

so i would not be focusing on that 23 feet as a plant buying guide ... i might be looking in the 10 to 15 foot range ...

but what you dont list in your scenario.. is what height you need to attain.. for the privacy ... surely its not the 23 feet the HOA discusses ...

a pic wouldnt hurt either ...

being a MI boy.. i have no clue as to plants to suggest ...

ken

"shrubs and trees never really stop growing ... many height estimates are at 10 years or so ... "

Well.......that's not precisely true :-) Mature size is genetically programmed into a plant and once they approach that size, growth slows to an almost imperceptible rate. There are all manner of shrubs that would fit your height limitation but how much spread can they have? Often shrubs will get nearly as wide as they get tall unless sheared to a more narrow profile.

I'd suggest you look at a few of these:
Laurus nobilis - Bay laurel
Myrica californica - Pacific wax myrtle
Pittosporum tenuifolium - Kohuhu
Podocarpus gracilor - fern pine

These are all evergreen, well-suited to SoCal and all are prunable to maintain a desired height and width. You can extend this list by looking at the Sunset Western Garden book - they list plants specifically for this purpose.

One thing you should be aware of is that plants have minimal ability to block sound. You would need a very dense and thick hedge (think forest) to achieve much sound blockage. That needs a solid surface, like a fence.

GardenGal48 has wonderful suggestions!

I am also in Southern CA (Orange County) and in search for tall shrubs in min space for privacy from neighbors. I've been doing so much research and those plants above are pretty much it.

Thanks for everyone's help. I have attached a photo of the area that I would like a privacy/noise reduction head. So far I am thinking about Pittosporum tenuifolium (kohuhu), Myrica californica (Pacific Wax Myrtle) or Ligustrum japonicum (Japanese Privet). As I mentioned before, the HOA will not allow anything that may grow over 25 feet according to the Sunset Western book. I would like something as close to that as possible. Again, thanks so much for your help.

Is it 23' max or 25'? You list two different HOA heights in different posts. It makes a big difference in the lists. Sunset uses 25' as the maximum height for many shrubs; if the HOA's max is 23', that changes the options. My sunset book (2012 Ninth Edition) lists P. tenuifolium at 15-25', Myrica californica at 10-30', and L. japonicum at 10-12'.

The pool is also a factor you did not mention in the first post, that is shown in the photo. Is the messiness of the plant to be taken into consideration? Are bees visiting flowers (privet), and possibly being stepped on by barefoot pool users?

Thanks for your reply. The official rule is that it cannot be higher than the roof line which is about 23'. I was told that they would probably be okay with 25', but I'm not positive about that. I honestly hadn't thought about bees. I did consider the root system. Honestly maintenance is already a pain because of a large pine tree (which is over 25', but no one seems to be complaining about it) which frequently drops needles into the pool.

I was thinking about L. japonicum, but I thought that would grow taller than 12'. I suppose I should look strongly at the P. tenuifolium since that might be might best option unless anyone has a better idea. Thanks again.