Let's see...

14" wide
10-15' high
No maintenance below 6'
No watering
No roots
Evergreen
Solid barrier

I can't think of any plants that meet that spec. Thought about something in plastic?

Why not just fill the 14" with concrete and build your wall higher?

14"? Could highway roses fill the spot? I know they get a lot larger than 14" but are they hardy enough to handle being sheared to 14" deep by however wide? It would certainly keep kids from hopping the fence. They don't get to 10 - 15' high though.

Definitely best to plant on your side of the brick wall with the screening plants that you desire, and if you want to plant at the outside of your wall, only a tough vine is likely to work. Even with a drought tolerant vine, I'd still recommend putting down a drip line on a dedicated automatic valve to get it established. Even if you don't plant anything, and just put down weed fabric and mulch, or concrete it, you'll still have some maintenance to clear out dead leaves/trash/weeds in that 14 inch gap. The double fence/wall at your property line is just a poor design, that obligates periodic maintenance to keep it neat.

There are plenty of choices for zone 9 slender/tall evergreen shrubs/trees, and/or clumping bamboos that would work, but other considerations beyond the height and size should be equal factors in making a decision on what to use. You should consider how much water they'll need, whether they should be hedged or left to grow naturally, whether adapted to your soil type, how they relate to the rest of your garden, etc. Just so you don't have unrealistic expectations, distance or a taller solid wall is a more effective sound attenuator than plants, or consider adding a water feature to create competing white noise.

Sunset Western Garden Encyclopedia offers an excellent section of shrubs/trees for screening purposes. You might also ask for advice from your local retail nursery.

The practical side of me wonders - to plant up the 14" between the fence and wall... will you be dangling a small child to dig the holes and plop in the plants?

With luck, the neighboring HOA has provided the appropriate trash recepticles for this public access. I'd get an industrial sized nozzle spray container of Round-up and keep the space at least weed free. I'd also invest in one of those long handled grabber implements for the beer bottles and paper trash that's inevitably going to be dumped there.

Plant on you side of the brick wall. I don't know plants/trees for your zone, but surely there's something that could start its branching or be pruned above the 6'mark.

Thanks everyone. These suggestions are really helpful. Based on the feedback I have received, it's seems that it'd be best to plant on our side of the wall. I'd have to agree -- this is the best option. The question now becomes WHAT to plant! The choices are endless, but I like the idea of a holly tree. I welcome other suggestions. It'll need to be dense to give visual privacy, and sharp or thick to deter "wall hoppers!" Thanks again.

Unless you've gotten feedback from somewhere else, I'm hearing something other here than advice to plant on your side. What you have is a design flaw, and no amount of compensation is going to create a really workable, elegant, maintainable solution. Far more logical to deal with it in a comprehensive, fundamental way, or it will be a nightmare for everyone who owns your home until your wall is replaced.

My question is this: why is that chain link fence there at all, and in that particular spot? Could it be removed? It seems to me it creates that horrid inaccessible ditch, and probably enables the boys to climb your wall. If the chainlink were gone, your wall would be a much more effective barrier at its present height. Removal of the chain link is the most effective solution for all your problems here. Then you could more easily get at that 14 inch gap to maintain it, or the HOA next door could do it, and you could plant your row of trees, if that's what you decide to do, more easily - and renew them as required.

Also, I think planting lots of something tree-like along the wall on your side will destroy your wall in the not-too-long run. Planting at the base of the wall will do it far less damage than creating root pressure on the wall itself.

If the chainlink remains in place, I would simply fill the gap with mulch on a regular basis, blasting weeds with steam or roundup as needed. For a screen to stop flying balls and boys, I would put up a series of very tall fence posts in the gap, which you may have to peel aside the chainlink to do, and then put lattice of some sort across them above the wall. Vines can grow up it from your side if you wish, but I don't know that you'll need vines or that they will improve things.

If you do posts, once they are in, you could even just give them 14 more inches of boat ramp.

KarinL

Karin, good suggestions. I appreciate all of your thought.

The chain link fence is there for a good reason. I'll try to explain.

Imagine you're looking down at the site from the air.

At the far left, you have my brick wall.

Next comes a 14" gap.

Then comes the chain link fence.

Then comes a boat ramp -- literally kissing the chain link fence.

Since the community lot's boat ramp allows access for a myriad of boat drivers (who have a varying level of skill when it comes to backing up a boat on a trailer), the chain link fence actually helps me because it keeps everyone who misses the ramp from knocking down my brick wall with their boat trailer. The sound of the chain link fence screeching along their boat trailer bumper gives people a nice "heads up" that they're missing the ramp!

If the chain link was down and someone hit our brick wall from their side (while backing into the lake), our homeowner's policy would go to their HOA for claims, since their lake lot is supposed to be used by their homeowner's only.

So....

The chain link (and that annoying gap) needs to stay.

So we're back to square one -- but a different square one than when this post started (you guys are really helping me -- thank you!):

- what to do with space between fences

- what do plant on my side that will create a pretty barrier between the two properties / discourage people from hopping the wall

Amazed at you guys and your willingness to help! Thanks again.

Are you allowed to put anything you want in that 14" gap? Perhaps you could put a trellis unsuitable for climbing that's as tall as your brick wall in the gap and plant a prickly vine to grow up it.

The explanation for the cyclone fence makes perfect sense now. If you aren't opposed to spraying herbicides such as Roundup between the fences periodically, this is probably the cheapest alternative to keeping it weed free. I had assumed with a zone 9 designation you might be in California, hadn't looked at the photos. I assume that you are somewhere in the south. Plant choices with thorny foliage might also include Osmanthus heterophyllus beyond the dozens of potential Ilex choices. Poncirus trifoliatus may be another good choice, but it isn't evergreen. Since the wall is bordered by a lawn area, you aren't limited to only using clumping Bamboo species, as runners are easily kept in place by simply mowing new shoots as they occur where you don't want them. Phyllostachys nigra might look quite elegant against the brick wall, alternating with shrubs/trees. One benefit of bamboo is that the noise they create in a breeze is a pleasant "white noise" effect that may help to cancel out boat ramp noise on breezy days.