When you harvest your seeds and you want to keep your seed sources separate. So if you harvest, say, five batches of broccoli seed one year, you want to put them each in a different envelope, label them as to the date of the harvest, the location where they were harvested from, and then what the seed is. And the reason you want to do this is that you want to note where you plant different seeds. Because if, say one of the broccoli seeds doesn’t come up at all, then you’ll know not to harvest those seeds and to replant those. And if one is very prolific, you might want to focus more on that.