Rostov is a traditional sunflower variety from Russia. It produces edible seeds and was quite productive here in Northern Indiana. The greatest difficulty I am finding with sunflowers is the increasing frequency of summer rainfall and high humidity. This can prove challenging to harvest quality seed without mold issues. I learned the hard way earlier this season with a large harvest of Peredovik sunflower heads. They were cut and hung in my drying shed to further dry. What I ended up with was 100% of the heads had molded. When I harvested the Rostov, I brought the heads into my house, where the humidity is lower. I laid them out on drying racks after “ripping off” the backsides of the flower heads to help them dry faster. Within a few days I removed the seeds and allowed them to further dry on the racks. This worked beautifully.
Rostov matures in about 70 days and has plants that reach about 6 foot in height with 12″ wide flower heads. I covered each seed head with a breathable mesh bag to protect from bird predation.