Helianthus 'Lemon Queen' is our favorite selection of the naturally-occurring midwestern US hybrid of Helianthus pauciflorus var. subrhomboideus x Helianthus tuberosus. In spring, Helianthus 'Lemon Queen' begins its climb to the skies and only stops when it reaches heights between 6' and 8' feet tall. In our garden, the sturdy stems are covered with 2" wide, soft lemon-yellow flowers in July and August. This clumping back-of-the-border sunflower is tolerant of either moist or very dry soils.