Solved Is this plant friendly?

It's sprouted in the garden of my new house. Growing rapidly. What is it?

 

Hi, and welcome to GC. I may be wrong but if it has spikey stems it could be wild Asparagus which pops up suddenly here.

 

I'm wondering if it's some kind of fennel!

 

Hmm, could be Clare. You'd know that by the smell.

 

Thanks for the quick responses! It doesn't smell like fennel and has perfectly smooth stems.

 

Maybe someone knowledgeable will now come along ...

 

Not really knowledgeable, but looks like my Giant Fennel (Ferula communis) can grow to 3m+, one of mine reached 12ft when in flower, large heads of yellow flowers attractive to insects. Mine self seeds but not ridiculously, can be monocarpic (dies after flowering), however mine behave as short lived perennials, took about 3 years from seed to flowers, but now flower yearly. The foliage does not smell of aniseed and it's definitely not edible. I will have a look for photos later.

 

Welcome to the forums.
Interesting.
Where do you live Timpwbaker.?
Don't expect sudden lush growth like that in winter in UK.

 

@Silver surfer good point, they are well on for UK.
Here in the South West this is what 3 of mine look like, all have different degrees of shelter



As promised flowering Ferula communis

 

It definitely looks very like the giant fennel, and the dead stems were left over from last year and were definitely 8-10ft with seed pods on the end when I moved in.

I live in South East London, the plant is in a sunny part of the garden when the sky is clear.

I'll let it flower and see. Will try to remember to post an update in the summer. Thanks everyone

 

@Timpwbaker That explains the lush growth the "London heat island"

@shiney The giant fennel is in a different genus Ferula to the garden fennel Foeniculum. Some forms of Ferula communis are poisonous to animals. My bronze fennel is also pretty much perennial, I lost it one year, but soon found a seedling. Some sources say that the giant fennel is monocarpic, my oldest one is probably 6 or 7 years so maybe not that short lived. I have had to remove a couple that got too big for their neighbours comfort, but they are generally problem free.