Posted: 17/05/2016 at 18:08
Pollination by other groups (standard or supersweet) will make tendersweet more tough and starchy. Why I do not know, but it is recommended that the three main groups, tendersweet, supersweet and standard are all grown separately to stop cross pollination, because of this deterioration in quality.
I only grow Swift F1which is a tendersweet. You do not get the tendersweet types in shops because they do not transport as well, too tender. the ones you buy in shops are usually supersweet.
They are wind pollinated, and it is recommended that varieties are at least 75m apart to stop cross pollination. If you are growing on an allotment, then get together with the others to find out what they are growing, otherwise you will all have tough kernels.