|Goldenrod flowers (Solidago sp.).|
Goldenrod and Ragweed
Prepared by Joey Williamson HGIC Horticulture Extension Agent, Clemson University, 02/14.
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There are approximately 28 species of goldenrods (Solidago spp.) in South Carolina, and they all produce masses of bright, golden flowers which light up old fields and the sides of our rural roads. Blooming typically begins in mid- to late-August and often lasts into early October. The Native American’s referred to the goldenrod as “Sun Medicine” because of its bright color and medicinal qualities. The intense color of their flower pigments have long been used to dye yarn.
Goldenrod & Ragweed CharacteristicsUnfortunately, the goldenrods share their bloom time with the inconspicuous ragweeds. It is the ragweed pollen that aggravates so many hay-fever sufferers, as ragweed pollen is wind-disseminated. Ragweeds (Ambrosia spp.) have greenish flowers on tall spikes and are not showy for attracting pollinating insects. They rely on vast amounts of pollen to be wind-blown to female flowers on nearby plants for their seed production.
|Staminate (male) flower spikes of common ragweed |
Goldenrods have heavier and stickier pollen that has been well-adapted for insect pollination. The bright goldenrod flowers are quite attractive to numerous pollen gathering insects, such as bees, butterflies, wasps and beetles.
|Wasp pollinating goldenrod blooms (Solidago sp.).|
Ragweed ControlOne may wish to remove any ragweed plants on the property when their growth is first noticed and before they begin making pollen. However, be aware that ragweed plants may cause dermatitis or rash if handled without gloves. Continued mowing will also prevent the pollen-releasing flower heads from forming.
Fireworks goldenrod in bloom (Solidago rugosa ‘Fireworks’).