Does anyone know what the name of a weed that looks something like a fern and grows very fast?

Question

I recently cut down a tree in my front yard. Since that time, I get these very tall and fast growing weeds. They look something like a fern or black locust leaf. The stalks are very hard. I can mow them down, but they keep coming back. They get pretty tall. Lots of little leaves very close together.

Answer 1

It sounds like bracken. They grow every where and they need to be dug up. They spread from root stock that can stretch a yard or more between plants. The stiff fronds can be very tall going over 6' in some species.http://en.wikipedia.org/wiki/Bracken
http://www.rook.org/earl/bwca/nature/ferns/pteridiumaqui.html
http://www.fotosearch.com/AGE004/e03-108727/

Answer 2

Might be Staghorn Sumac (Rhus typhina). What kind of tree did you cut down ? This might be that tree coming back . Another possibility could be Tree-of-Heaven ( Ailanthus altissima ) . Like Sumac it is in the cashew family (Anacardiaciae) , and has a similar appearance . Crumple the leaves. If it smells something like stale popcorn it is this tree . Lastly, might be Honey Locust ( Gleditsia tricanthos ) . The leaves are more finely-textured than Black Locust , & brighter green , without the hint of blue that Black Locust has .

http://www.ces.ncsu.edu/depts/hort/consumer/factsheets/trees-new/rhus_typhina.html

Answer 3

If it is sumac you can dig them up and make them into bonsai's. They have the most beautiful blood red leaves in the fall. Even if it's not a sumac you can do so with the seedlings.