I believe adding a Lady Banks rose would help. It can take 2-4 years to reach a mature size but one bush can take up a considerable amount of wall space and the neighbors watering will only help it establish the root structure sooner. A Lady Banks is typically a once-a-year bloomer, is sold with the landscape shrubs in nurseries and only requires the occasional shaping with hedge shears to stay tidy. While it is a rose bush, it is not treated like the modern roses that most folks think of. Fertilize it 2-3 times a year with a low-nitrogen, slow release fertilizer like Osmacote and apply chelated iron once during the fall and again in the early spring when the rose is actively putting out new leaf and bud growth. Just remember when you plant the bush, it will grow huge roots so a little 10"x14" hole isn't going to allow for that growth. Roses tend to need an 18" depth hole and a minimum 24" wide so a Lady Banks would probably appreciate an 18"x36" wide hole with a 40% existing soil mixed with 50% planting mix and 5-10% potting soil or sand. You could also use a fine-grade compost instead of the planting mix/potting soil/sand. If you've already amended this area a great deal, you may only need to add some compost at planting time and a little sand or cactus mix to help with drainage and aeration.

I think I may need to plant some of these. Thanks for the tip and planting recommendations!

Thank you for the suggestion of the Lady Banks, as it takes 2-4 years for them to establish and it looks like they do a better job hiding the upper part of the wall once they are, I'd like something that grows fast.

Coral Vine/Queen's Wreath (Antigonon leptopus) does VERY well, even on a south-facing wall. It blooms beautifully, tiny, bright pink flowers, practically all year 'round. You have to train/support them, but they do grow fast. If there is a hard freeze, they will die back some. About four years ago, there were several hard freezes in a row and ours died back to the ground, but came back up from the roots. WONDERFUL plant for hot AZ.

Thanks Karen, I'll have to look into the Coral Vine. I looked it up and it certainly is pretty.

I have a block wall as well. If the staining you are refering to is this white discoloration it is from the salts leaching out of the block. Their isn't much any one can do about that. My neighbor has complained about the same thing to me where I water the grass even though the water does not touch the wall. I have explained to them I am not getting the wall wet and there is nothing I can do about it. I also have it on the block at the top of the wall, next to gravel(no plants) which gets no water what so ever. I agree it is not very attractive but aside from sealing the wall every one that has a bock wall has the same experience some time or another. Sorry

The water may not touch the wall but if a yard or plants are over watered, the water can find it's way through the soil and into someones yard, especially since lots are pitched some what for drainage. I have other photos that show it flowing into my yard in one area. What this neighbor is doing is a code violation for the city of Goodyear. It's the soaking of the wall daily that bothers me not just the white marks. Since they will most likely continue to be inconsiderate and not do anything about it, I'm forced to spend more money on my yard to hide it. I'll be having dirt & rock hauled in to make mounds and dress them up with some desert plants.When, not if, the wall does fail, I'll be taking them to court.

sdcatgirl- I tell buy your responds that you are very fustrated with your problem. It is a tail tell sign that you are not from Arizona. Ok with that said I am going to give you some sugestions. With out spending a ton load of money.
The best way to sove the problem is to buy a wagner power painter about $75 @ Home D and buy stain and sealer combined in the paint department for celdar block. You can do it you self for about $150 maybe a little more. ( If I can do it so can you, I am a women)You can also select a color maybe a nice brownish or the color of the around the pool/house. It will hide everything, not gravel or plants etc mucho $$$$.( It will always be there) It drys fast so no waiting and will last for a few years. After you can say you did yourself and be proud, if not you can hire some one do the same thing. No more problem. This will be alot cheaper in the end then what you plan to do. with the left over in a few years if need be you can do it again.