I did some 30 years ago grow a tree from seed (a COX PIPPIN) with some Success I may add after 4 years it showed blossom but no fruit the 5 year it gave me fruit and very good fruit. I would plant the seed and let nature takes its course nothing ventured nothing gained. and trees have been growing from seed by there selves since time began. I would sow it now out doors in a pot – or force it by growing in doors. - Ken

ps/ I have a damson tree I may just try and grow another from seed this year.

Hi, as the seed is 20 years old, there is a good possibility that it is no longer viable, but you have nothing to lose by sowing them in a pot or tray, and see what happens, if they don't germinate, at least you will have learned that this particular seed does not keep for 20 years, Derek.