Hoary skullcap (Scutellaria incana) is our Plant of the Month for September 2026. This native perennial comes from the Upper Midwest Region, along the slopes of the Appalachian Mountains and west to the Ozarks. It is one of 44 species of skullcaps in North America.
Although only found in 1 Kansas county (Cherokee), it can be found in the eastern portions of the Central Great Plains Region. A member of the Mint Family, Hoary Skullcap (also called Downy Skullcap) grows 1 to 3 feet tall and wide, and can spread from seeds or rhizomes.
In the Garden
Hoary skullcap is a great perennial plant addition to the garden. When we first grew it in 2024, I was a little skeptical, having very little knowledge of this plant. But after adding it to my own gardens, I was very impressed.
In the wild, hoary skullcap grows in dappled to partial shade mainly, similar in habitat to purple milkweed (Asclepias purpurascens). But in my own backyard in Northeast Kansas, I had it placed in full sun, and it did very well, blooming continuously from July to October.
It was one of the showiest plants in my garden. And the purple-blue flowers were a refreshing addition to a garden full of pinks/yellows/oranges. I think it would be a great addition to my meadow garden, and it would work well in glades, meadows, and woodland edge gardens.
Pests and Pollinators
Because hoary skullcap is a member of the Mint Family, it has a strong odor when crushed and is rarely eaten by either rabbits or deer. There are only a couple of insects which feed on the foliage, including 2 moths and 2 species of flea beetles.
It is called skullcap because of the skull-shaped calyx on the top of the flower. Because of its shape, there are not as many pollinators as sunflower or other plants with more accessible flowers. However, there are still several insects with pollinate on the flowers including:
- Bumblebees
- Carpenter bees
- Silver spotted skipper
- Bee flies
- Other skipper butterflies
- Wasps
Companion Plants
In my own garden, I have not done a great job of pairing this wonderful perennial with similar blooming or sized plants, but I plan to do more in the future. A new cultivar of hoary skullcap will be available in 2026, 'Prairie Snow', which blooms white. Pair skullcap with the following plants:
In Partial Shade/Dappled Shade
- Purple milkweed
- Globeflower
- Obedient plant
- Elm-leafed goldenrod
- Zig-zag goldenrod
- Willowleaf bluestar
- Common boneset
- Late boneset
- Purple Joe-Pye Weed
In Full Sun
- Agastache 'Blue Fortune'
- Common Milkweed
- Purple coneflower
- Pale purple coneflower
- Prairie blazingstar
- Fall phlox
- Rattlesnake master
- Common boneset
- Culver's root
- Willowleaf sunflower 'Autumn Gold'
- Red Hot Poker
Conclusion
Hoary skullcap has not only an interesting name, but is one of the showiest perennials in the garden from July to October. The bright blue-purple flowers (or white) shine in the garden.
Happy planting!
