You may well find that it's self seeded whether you wanted it to or not! I had one in a pot once and the paving nearby was never free of its seedlings again - but I liked it popping up where it wanted.

I expect just collecting some seed heads when they're ripe and shredding them where you want some borage next year will be enough.

Thanks ! yes i have to change the garden next year so i wanted to make sure i have seeds as the place its in now will be no more! i wiil give it a try .