My garden is so closely planted, it's almost impossible to save seeds that will come true to the parent. I have tried pollinating/isolating blossoms with dismal results. It's just easier to buy or trade for the seed I need. There are a few things I don't mind planting crosses of....zinnias can be beautiful when planting seeds saved from hybrid parents. Tomatos, when they are something totally different are not such a fun surprise. It has given me a new appreciation for why seeds sometimes cost as much as they do. I'd rather pay the price than do the work involved.
