Its got me beat, the Pink Beauty radish i sowed well away from the flowering Black Spanish is bolting also. So i'm wondering if the warmer than normal summer has something to do with it. Just seems odd that one summer nil bolters, next summer dam near 100%, same lot of seed.
Its odd how it goes sometimes, ive had no bolters in my parsnips (sown late winter) and one in the turnip bed (sown late spring). Cant include the carrots though, the seed was given to me by a bloke who clearly had QAL growing nearby, half the sowing has been pulled so far and most of them had the narrow white roots, but cant complain can ya when ya given the seed.