S Bengi wrote:My formula for a guild on a city lot
N-fixer (dutch clover, etc)
Insectory/Pest Control (Mint/Thyme family)
Soil Pest Control (Onion/Garlic Family)
Soil Aerators/Miners (Daikon Radish, Comfrey/Borage Family)
I would add Eleagnus as a great nitrogen fixer as well. Tolerates all kinds of soil as long as they don't sit in water all the time. Grows fast (lending itself well to the chop-and-drop method of mulching) and sheds leaves that form a natural, weed-blocking mulch in place. Some varieties also have edible fruit (goumi, silverberry, etc.) that can be used for juice, jelly or chicken treats (they LOVE the red, juicy berries I toss out in the yard for them). Plus, when they bloom, they are covered with tiny, creamy white, sweet-smelling flowers that the bees LOVE.
A few words of caution - some varieties are considered invasive and may be illegal in parts of the US. Also, if you aren't going to chop-and-drop new growth for mulch, a bush can quickly overtake anything planted within 6 - 8 feet of it. You can also cut the long canes of new growth they produce every year as flexible staking and woven/wattle fencing.