Don't eat it, we might not hear from you again!

Well if they are 6 - 7 inches high they've been growing for a while and you simply haven't noticed. Photo will certainly help with i.d.

I have just pulled out a plant which exactly matches this description. I let it grow out of curiosity but it has got so big that it was obliterating some of the rose blooms. I, too, wondered whether it was a lettuce but I've never seen one grow so tall!

No, you're right Cammomile, I resisted the temptation, just in case, so didn't sample it.

It really was that quick, Moon Growe, I had hoed around the bushes removing tiny new shoots (a stitch in time philosophy) just before leaving to spend a week with my daughter. It was about the 3rd day on returning that I found time to go out to water etc and there they were!

I can't really see clearly the plant in your picture Penny, it's not close enough. The way you describe it, it could be the same plant. Like you, I too am letting them grow for a while, just to see what happens, or at least until I can get a connection lead camera/computer to post some pics up.

Thanks all.

Personally if you did not plant I'd ho or pull out - before they flower!