I am a newbie at gardening, and was wondering if there is a difference between the seeds in the UK, as opposed to the US? Does it really matter which are used if the climate zone is similar, or if a grower has a greenhouse to their advantage? Thanks in advance to any who can answer this one for me.

Also, if there are seeds that someone wants, and has a hard time getting hold of, I will be happy to try and find them and help in any way I can.