Unfortunately the current Covid19 situation has resulted in a lack of available vegetable seeds and seedlings, but don’t despair if you still have some seeds from last year or even the year before hidden in the back of your laundry cupboard. In many cases these seeds can still be viable if treated correctly.
Seeds have a date that is essentially a best before date, after which the seed viability drops off markedly. Seeds such as chilli, capsicum and even corn have a short shelf life, but now is not the time to plant these anyway. Unfortunately onion seeds fall into this group as well. Other seeds such as beans, peas and the brassicas are often good for up to 3 years, and others such as lettuce and radish are good for 5 to 6 years.