[treacleminer]

Jersusalem Artichoke 

I've dug through where it was last year (and overlapping the year before) 3 times now - whats the betting more will still come through next year??

Any other horrors I should avoid
Janet

PS the hens were happy with all the digging though

[Trillium]

I believe the saying with JA's is: once you have them, you'll always have them.

Other than JA's, I think some of the herbs are horrors, like all the mints, catmint, lemon balm and feverfew (a flower). Can't think of any other veggies that are a problem like that.

[richyrich7]

Comfrey it's like twitch once you have it you can't get rid and if you chop it up you get more.
Just glad it's so useful 

[shaun]

horse raddish

[Trillium]

Horse radish is not a veg, but it is a huge pain in the **se if it gets a foothold. And we don't have the hybrid comfrey you have in the UK, just the big monsters with roots to china, which is why I've planted mine around the huge acer trees where they're okay but struggling. That'll teach them  A friend of mine mistakenly planted hers in the flower garden and regrets it every day.

[Stripey_cat]

Rocket self-seeds crazily, but is at least easy to hoe up!  Plus chickens would make short work of it.  Do you know anyone with a pig you could borrow to get the JAs?

[Ice]

On reading this I'm so glad I planted my JAs yesterday.   As for the wind problem, I'm going to get a small turbine attachment for my backside.

[FCG]

Ice with the reputation some people have after eating JA i think you'll be self sufficient with energy if you did that!

Best thing i've seen is a photo of someone growing JA in a bath with the plug in. That is ingenuity! If that is you please come forward to collect your award.