How to save seed for heirlooms plant?(remain purity)
I have some heirloom tomato(Rutger) and other plant. I wonder is there any way to save the seed and grow into the same plant as their parent(remain purity).
Should I use self-pollination or sow two~four of the same variety, then hand pollinate them(isolate them from other tomato variety)?
Anyone know what technique commercial grower use to achieve this purpose?