The Great Sunflower Project

this is the 2nd year i have tried to participate in the sunflower project and had my sunflowers attacked by some insect, parasite, or something that kills the flower bud and does not allow it to reach the blooming stage. both years, i had 5-6 nice tall sunflower stalks but none have bloomed. any suggestions for how i might participate next year? i am reluctant to send for the official sunflower seeds from the project, i would hate to have them wasted here again.