At B&Qs' across the country they are now, or about to bring in the new lines for ferts & chems, which means that they will be selling off discontinued lines. A lot of them are still sold, but they have different packaging & have a different bar code so they are sold off too.
Depending in the store manager, the lines could be sold off for 50p - £1 so it's worth a look-see. :)