Goldenrod s. Ragweed

Don’t Blame Goldenrod for Your Allergies!

Do you know the difference between goldenrod, Solidago species, and ragweed, Ambrosia species? There are over 75 different species of goldenrod and 20 species of ragweed native to the United States. Goldenrod is usually blamed for seasonal allergies, but the real culprit is ragweed. Both are in the Asteraceae family and can be found growing in roadside ditches and open fields. They also bloom at the same time. Goldenrod flowers contain nectar that attracts pollinators, and the large heavy pollen grains attach to the insect bodies. Here’s the difference. Ragweed flowers do not contain nectar, and the plants are dependent on the wind to transfer the small, lightweight pollen. This pollen can blow for miles. A single ragweed plant is able to produce over a billion pollen grains. HGIC 2326 Goldenrod and Ragweed

Goldenrod is perennial and typically single-stemmed or somewhat branched near the top of the plant. Ragweed plants are annuals and highly branched from the bottom upward. Goldenrod foliage is not divided or dissected, as with ragweed.

Goldenrods have heavier and stickier pollen that has been well-adapted for insect pollination. The bright goldenrod flowers are attractive to numerous pollen-gathering insects, such as bees, butterflies, wasps, and beetles. Songbirds eat the seeds.

Ragweed has greenish flowers on tall spikes and is not showy for attracting pollinating insects. Ragweed relies on vast amounts of pollen to be wind-blown to female flowers on nearby plants for their seed production. HGIC 2326 Goldenrod and Ragweed

Ragweed grows in poor soil and is drought tolerant. In the fall, copious amounts of pollen is dispersed by the wind and the seeds can remain viable for several years. Birds and game birds love the seeds for the high oil content. HGIC 2326 Goldenrod and Ragweed

Goldenrod has a medium flammability rating and is moderately deer resistant. It supports the Wavy-lined Emerald (Synchlora aerata) larvae. Members of the genus Solidago support the following specialized bees: Andrena (Callandrena s.l.) asteris, Andrena (Callandrena s.l.) baccarat, Andrena (Cnemidandrena) canadensis, Andrena (Cnemidandrena) hirticincta, Andrena (Cnemidandrena) numecula, Andrena (Callandrena s.l.) simplex, Perdita (Perdita) octomaculata, Melissodes (Eumelissodes) fumosus, Colletes simulans, and Colletes solidaginis.

When planning your perennial or native flower beds for next season consider adding solidago. You will attract many pollinators to your yard, and this plant will not cause you allergy woes.

Photos and information by Jeanne Pavero, North Carolina Extension Gardener Plant Toolbox