and hard to eradicate; however I bet the city has loads of rats in places without plants (that's why rats like cities!) You put traps down for the rats, that's all; later on if you build up a nice ecosystem predators will cut down on their numbers but that takes time. I do think there are certain plants that favor rats; Mondo Grass (the higher kind) grows well in shade but provides rats with excellent cover; I knew someone who had to pull all of hers up when she found all of the rats nesting in there.
Here in New Orleans we have lots of trees (lots of crime too...) Careful pruning makes for safety. Many of the enourmous ligustrum have been trimmed to multitrunked trees and as the trunks are not very big nobody can hide there.
You have to also consider what's NOT being said by the authorities; which is that bushes and trees that offer shade can make a park inviting to homeless people who are then very hard to get rid of (they have more rights then rats but are almost as disliked.) If you consider this in your plans for a greenspace, you might be more able to succeed. It's awful but true; the homeless need a home but the local park is not it. The 'security' bit may well just be an attempt to curb homeless people squatting in a park. The obvious follow up to this is that the entire un-enclosed area of a city must be made as miserable as possible to avoid homeless people making it a home; if you make this point maybe they will reconsider landscaping of the park. There are little trees which don't interfere with overhead wireing, close or thorny groundcovers which curb rodents (and squatters!), and there are low-matinance plants which could be used (cacti? purslane?). Try some research into the local favored plants in your area (I myself do not know what grows best there). Believe me, there is a solution; unfortunatly those in power are often too busy or (alas) lazy to find it out. You may have to do the legwork (and brainwork) for them. Of course they will grab the glory when it's done, but hey, you'll have a park.

I am so impressed by what you have already accomplished! you have someone listening to you and making concessions. your continued effort will make this project happen. I will look for resources to answer your questions and post again, but I did want to congratulate you on what you have done so far.

jessie

Thank you for changing your corner of the world. Your English is very good--no need to worry about that!

What is the garbage situation like in the city? Is garbage easily gotten to by rats?

I live on a farm and rats are part of life here--you can expect rats if you are surrounded by acres of corn, soybeans, etc...

But we do what we can to make our animal feed unavailable to the rats in the barn. There is an electronic rat zapper I'd like to get.

I saw something about an amazing Mayor in South America (Caracas??) who cleaned up a slum area creating an eco-friendly clean park. He gave jobs to the jobless to accomplish this. The water supply was improved and no more flooding on the poor. Anyone? They used landscaping to accomplish their goals. Wonder what happened to that guy--sure would like to read more about him.

His name is Antanas Mockus -- yes, it was Bogotá. Very interesting guy! He also improved city traffic by using street clowns to embarrass inconsiderate drivers. I'm not sure if he's still the mayor or not.

You're going to have rats whether you have plants or not.

Security is a big issue. Bushes are the worst for security, worse than trees. Easier to hide behind a tall bush than a skinny tree trunk. There are trees that do well in cities with all the pavement and air pollution but what would do well in the warm climate of Mexico DF I dont' know. Ficus benjamina does very well in Hong Kong, another very dense, polluted tropical city, so should do well for you too. Norfolk Island Pine (Araucaria heterophylla) grows all over other parts of Mexico. Crape Myrtle (Lagerstroemia indica) is a good small tropical tree. Gingko takes city conditions and comes from warm parts of China so should take Mexico DF's climate too.

Bougainvillea and climbing roses are often used as security plants in tropical areas as they are very thorny. Natal plum (carissa macrocarpa) is also tropical and thorny but produces little fruits that would probably feed the rats. Oleander (nerium) grows everywhere in Mexico but is a big bush that people could easily hide behind. New Zealand flax (phormium) has very soft, grasslike leaves and would not get broken by people pushing it. Dwarf ones are very short like a ground cover almost.

friends of mine breed falcons (mainly peregrines for hunting). you feed falcons with mice, guinea pigs, 1day chicken or rats. some of the rats escaped. the bred well. the bad thing about them was that we don't like rats and that they did a lot of digging. so the rats were killed, probably hundreds of them, could also be they moved. the falcons got really sick, not because of the rat poison. falcons like to stash their food. and it's no good idea to stash a chicken when it's hot (a 1 day chicken is not much more than an egg ...). the rats had been the only ones who really cleaned up! - martina

I really think it is great what you are doing. You are trying something that most in cities would love to do, make it more liveable and make the environment better. Ever check out vermicomposting? You can make great fertilizer with compost redworms.

I like the plantain trees in my garden, they make lots of excess leaves that are good for my compost pile. I do not have grass clippings available to me, and here where they spray constantly, I wouldn't use the bagged stuff along the road either.

As the other poster said, Ficus trees or banyans are great and put out lots of leaves too. I have both right next to my little plot.

Good luck to you in your efforts to green your part of the world! I applaud you!!!!