FLOWERS / BELLFLOWER Blue Throatwort. This member of the campanula family blooms with large spheres of tiny, starry, tubular flowers. 24-36" tall x 24-36" wide. Hardy to Zone 8 or so. Annual elsewhere. $3 Add To Basket Listed In: 2021, 2023, 2024, 2025 Wyoming USDA Hardiness: 5a View Profile & Listings