Jen, I see you live in Cheshire and involved in horticulture, Have you ever been to Fouroaks?
http://www.fouroaks-tradeshow.com/ if not then you should pay it a visit (Sept) and see the foreign exporters trying to sell stuff to the UK. it will open your eyes to the problem and just how large the market is, at one stage a few years ago, the plant auction at Aalsmeer in Holland
http://www.floraholland.com/en/about-fl ... ion/eelde/ was the largest commercial building in Europe.
I can guarantee that more than 90% of the plant stock in every single garden centre in the UK has originated from overseas and most of the UK wholesale nurseries buy their stuff from Italy or Holland, it's just too expensive to grow it yourself, wholesalers can order an artic load from Italy and it will be on their doorstep within the week, so much more cost effective to buy it in at prices the British growers cannot match then sell it on at a very good mark-up, then the garden centres add another 2 to 300%.
Andy