[Mr Dog]

For an idea of how quickly they can spread/take over I harvested my 1st pot of JAs today. From 4 tubers planted in a 50L pot filled with 'old' compost I got 58 tubers.

[Longshanks]

Can I buy JA from a supermarket and plant them or do I need to buy from a proper supplier?

[Mr Dog]

Can I buy JA from a supermarket and plant them or do I need to buy from a proper supplier?

I don't see why not, although they may be treated to delay sprouting. I got mine from a well known auction site which were cheaper than the supermarket.  I've harvested and used mine now otherwise I could have popped a few in the post for you.

[Longshanks]

I think I'll give it a go by buying some organic ones from the supermarket. I'll dig a plot and put some boards down around it maybe a metre+ down to stop them spreading. Maybe deeper.

[Longshanks]

My supermarket bought JAs are now growing well. Looking forward to a decent harvest.

[SnooziSuzi]

 

... a sound not unlike the theme from Johnny Briggs

I had completely forgotten about the tune until you mentioned it there and it all came flooding back! 

Parp, pup pup pup pup pup pup pup, puddadadadudadaaa 

[SnooziSuzi]

I like them.  To echo Mr D; if we all liked the same things life would be boring

I put 8 tubers in earlier this year and some have shown signs of life, but I've kept the bit they are in sectioned off with a deep bit of plastic window sill.

I had them at my previous allotment and didn't manage to harvest them all one year and I swear there was about 4 times as many stems the year after!