seeds

I you are after the basics, then the supermarkets, or stores like Wilko are as good as anywhere else.
If you fancy something a bit different then there are a good few seed suppliers on-line or they sell their lines in the garden centres.
When there are seed sales on we post them in Frugal Living, https://chat.allotment-garden.org/index.php?board=9.0
so you can pick up some bargains through the year