Our July Plant of the Month for 2025 is Curlycup gumweed (Grindelia squarrosa). You have probably never heard of that eh? Well, this little known perennial native is actually quite common across much of North America. The only place it does not grow is along the Gulf States, except for Texas. It is quite common in Kansas and the Central Great Plains Region.
A member of the Asteraceae Family, it is related to sunflowers, black-eyed Susans, and daisies. Just like them, it has compound flower heads , comprised of both disc and ray flowers. This means that there is ample space for pollinators to land. Its called gumweed because it exudes a sticky resin on the leaves, stems, and flowers. Curlycup gumweed also has extra-floral nectaries, which are glands on the outside of the flowers that produce nectar.
Uses in the Landscape
Outside of native plant societies, I doubt anyone has used curlycup gumweed in the landscape. But you should think about it. Not only does it bloom from June to October, but it is extremely drought and heat tolerant. It was one of the few things which thrived during the early fall drought of 2024, when I had 7 weeks with no precipitation.
It can be planted in a variety of places in the garden. I like to use it for cut flowers, because they do last a long time. Plant it in full to part sun, in tough sites like a west facing garden bed. It will grow 3 to 4 feet tall and 3 feet wide, sometimes like a small bush, and sometimes straggly (if it gets too little light). One of the best places for it is a dry, well-drained area such as a rock garden or dry prairie. It does very well in my meadow garden.
Historical Uses for Curlycup Gumweed
Gumweed contains resin, volatile oil, an alkaloid, flavonoids (luteolol, quercetol, kaempferol, and quercetin), tannins, saponins, and phenolic acids. These various plant compounds have be utilized by Native Americans, the Spanish-Mexicans, and the US Pharmaceutical companies.
The Native Americans across the continent used curlycup gumweed for a variety of ailments. Secretions of the gummy resin were gathered and used to treat bronchitis, asthma, and colic. Early settlers used to chew the resin in place of various other “gums” which were also various resins from spruce, pine, or fir. It was consumed as a tea for coughs, tuberculosis, and dizziness.
Insect and Animal Associations
I have yet to see a disease on this perennial, but it may get powdery mildew if put in a wet or shady spot in the landscape. There are 7 species of moths which use curlycup gumweed as a host plant, and roughly 10 other insects feed on it. But the best reason to have it is that it is host for 68 pollen specialist bees. That is a lot of specialist bees, and many of them may be imperiled or endangered. The flowers are also visited be various other bees, wasps, butterflies, and other pollinators.
Because the plant exudes resin and contains a variety of flavonoids, animals do no eat it. It is deer, rabbit, bison, and every other mammal proof. Also, birds rarely consume the seeds.
Companion Plants
Curlycup gumweed can be grown alongside a lot of other, similar prairie plants. I would suggest mixing it into a bed or border along with native grasses, and any of the following perennials/annuals.
- Butterfly milkweed
- Dotted blazingstar
- Ornamental onion
- Baptisia australis
- Black Sampson echinacea
- Rudbeckia ‘Little Henry’
- Rudbeckia maxima
- Hairy aster
- Aromatic aster
- Sneezeweed ‘Dakota Gold’
- Eryngium leavenworthii
- Lavender
- Penstemon cobaea
- False sunflower
- Rose verbena
Conclusion
Curlycup gumweed may be the perennial you have never heard of, but I am telling you that it is one of the best plants for bees, especially native bees. Put it into the driest, hottest spot of the yard, and watch it bloom from June to first frost. You will not be disappointed.
Happy planting!
