Hi there,
I run a one acre walled vegetable garden in Hampshire, and we use 50-cell trays made by Teku (which is owned by Poppleman, a German company I believe). We have had ours for many years, and treated with proper care they last for quite a while. They’re not rigid, rather flexible actually, but the bottoms hardly ever crunch when you push the plugs out.
They’re sold in the UK by a couple of companies:
LS Systems [for market growers, 180 trays for £100]:
http://www.lssystems.co.uk/index.php?main_page=index&cPath=837_1075_841
(The “TEKJP305050 P” trays are the ones that we use).
And also by LBS Horticulture [5 trays for £6.24]:
http://www.lbsgardenwarehouse.co.uk/product.asp?src=BGWebsite&pf_id=TPLUG&name=teku&sfile=1&jump=8
I’d also like to reiterate Andy’s original comment, and say that I too have been greatly inspired by you Charles. I bought all three of your books, and they’ve helped me SO much – we’re growing 1/3 more veg. inspired by your ideas of crop succession, including more winter veg. and lots of different salads this year. I can’t wait to come for a course this summer and learn more about your no-dig method!
Matthew