Chicory is a perennial and one that many consider a weed; it certainly is persistent enough. Formally known as Cichorium intybus ), it is a member of the family Asteracea.
Chicory is well know, the roots, that is, as a coffee substitute but if I was to wild cultivate it for this or any other edible purpose I would want to know more about the soil where it is growing.>
The young leaves can also be used in a salad. However, once again if I was planning to wildcraft the leaves I would need to know more about the site other than chicory was growing there.
For example, how long has the site been abandoned, in an urban setting, there can be a number of areas where buildings once stood but have come down for one reason or another. Depending upon what the purpose of the building was, for example, industrial, and how long ago it came down, you may just want to enjoy looking at the wild things rather than eating them.
You could collect a soil sample and get it tested, at your own expense, if sufficiently motivated.
If the motivation is strong within you, take a trip to the local municipal office and find out who owns the property and gather all the information you can.
It may be worthwhile to contact the owner and find out what you can about the site. Meanwhile enjoy the wild garden. Nature is a fine gardener, observe and learn.
