Scutellaria species

5/28/2024 11:57 am

 

 

About Scutellaria

 

Scutellaria are flowering perennials in the mint family with the characteristic square stem and recursive leaf veins. There are approximately 300 species around the world. There is quite a bit of diversity found in the leaves and stems of the different species but much less in the flowers. A number of available species make attractive garden plants. Other species are somewhat coarse but certainly worthy for consideration in native gardens.

 

Scutellaria means "little dish" which refers to the covering of the calyx. The flowers look like either mini snapdragons or a medieval hood or helmet.

 

Scutellaria serrata close up - photo by Liane Schleifer

 

Scutellaria, native and nonnative, have been used an ingredients in herbal medicines for centuries in sedatives and for anxiety relief. These plants have bitter tasting leaves so are usually ignored by deer and rabbits.

 

Most forms originating in the United States do best in ordinary garden soil with some shade. The exception is Scutellaria suffrutescens (Texas Skullcap), which thrives in the rock garden, loving full sun and faring well in bone dry circumstances. There are quite a number of Mexican species that are also sun loving, but they are rare in the U.S. trade outside of Texas nurseries.

 

As members of the mint family, it should come as no surprise that many species of Scutellaria are aggressive, including many of the domestic forms like S. incana, S. nervosa and S. ovata. 

 

Scutellaria attract both bees and hummingbirds.

 

Some Scutellaria Species to Consider in your garden

 

Scutellaria suffrutescens, which I bought labeled as Texas Skullcap, is indigenous to Mexico with some evidence for a slight native presence in Texas too. It is a personal favorite, a small shrubby skullcap with very tiny roundish leaves that gets to 10 - 12 inches tall. In mild winters, they may even remain evergreen in metro Atlanta and southward.

 

S. suffrutescens is a great performer in metro Atlanta with an extended bloom time (aided by deadheading) and bees love it. I've had it in purple and cherry red. These plants can last many years too. The challenge has been sourcing these locally. You can find them online, however.

 

Scutellaria suffrutescens close up and in the rock garden - Photo by Liane Schleifer

 

Scutellaria incana has a verified native presence in metro Atlanta. The foliage is bright green with tiny ovate leaves and the typical bluish purple flowers. It is called "Downy" or "Hoary Skullcap". It might be edge of meadow worthy, but is kind of coarse for the border to me. Also, it spreads by rhizomes as well as seeds, making it a real aggressor in the garden. It grows tallest of all the nearby native forms, 2-3' tall, and grows in a bushy form.  

 

Scutellaria incana - Photo courtesy of Plant Delights Nursery

 

Scutellaria serrata is mainly native to the Mid-Atlantic region, but is found to some degree in the utmost northeast corner of Georgia. It has the typical flower shape in a bluish purple, grows about 10-12" high and frankly is notable for its pretty foliage -- a good bargain from a plant that doesn't bloom very long. Its large ovate, deep green leaves are ringed in purple. This becomes more defined and prominent after the bloom. Very sweet!

 

Scutellaria serrata in bloom (left) and post-blooms (subtle purple leaf edges) - Photos by Liane Schleifer

 

Scutellaria ovata (Heart-leaved Skullcap) had short presence in my garden. The Biota of North America Program (BONAP) notes native presence of this plant in one adjacent county to metro-Atlanta (not mine).* Otherwise, this is a Georgia northern fringe plant -- also found quite a bit to the north as well as in Alabama, Louisiana and the Heartland. The blue flowers sport a white tongue which pops nicely against the dark foliage. I would try it again for its attractive foliage as much as the blooms, but more at the edge of a moist woodland than my part-shaded dry rock garden.

 

Scutellaria ovata - Picture courtesy of Plant Delights Nursery

 

 

Scutellaria multiglandulosa ‘Laurens’ has also died at my hands.  (You may have noticed a theme. I could be a serial killer -- of plants at least!) This is a strain grown from seed from Laurens County, Georgia (around Dublin). It is mostly a Floridian plant with some presence in lower Georgia. I probably grew it a few years before we started heating up so much and became a new zone. I would try it again as we get closer and closer to Florida like weather! It's short (to 10" tall) and has attractive purple stems with narrow leaves. 

 

Scutellaria multiglandulosa 'Laurens' - Photo courtesy of Plant Delights Nursery

 

Scutellaria integrifolia has some native presence near metro Atlanta and more throughout the state. It looks quite a bit like a larger form of S. multiglandulosa without the dark stems (but I have not seen it in person). Beech Hollow Farms in Scottdale offers this for sale.

 

Scutellaria integrifolia - Photo courtesy of Plant Delights Nursery

 

Scutellaria longifolia is a plant I lust after, with rich fucshia pink tubular blooms that shout "hummingbirds visit me". This one is more of an annual here, although it might survive with heavy mulching.  Online sources at publication time (Spring 2024) include Almost Eden Plants.

 

Scutellaria longifolia - Photo courtesy of Almost Eden Plants

 

 

My best growing Scutellaria is S. indica var. parviflora. It is essentially a ground cover. And like many Scutellaria except S. suffrectens, it is aggressive. In the rock garden, it dukes it out with Campanula poscharskyana (Serbian Bellflower) and Achillea ‘Desert Eve Deep Rose’ (Yarrow). It also shows up in my pots below the rock garden. At a few inches tall at most, and a repeat bloomer, it is hard to resent its presence (although I do pluck it out of containers to reduce competition with other small plants in them that might not be as aggressive). It recently found its way across the driveway too. I share it with folks with a warning. On the other hand, it is a great green living mulch, loved by native bees and since it is so diminutive, I doubt it would displace any natives were it to escape . . . . but caution is advised. 

 

 

  Scutellaria indica var. parviflora  blooming and post bloom - Photo by Liane Schleifer

 

 

There is also a white cultivar called 'Snowflake' that is very charming.

 

Scutellaria indica var. parviflora 'Snowflake' - Photo courtesy of Sieglinde Anderson

 

 

Indeed, I reiterate the caution about aggression for all but the Texas Skullcap. One of our local native plant nurseries, Beech Hollow Farms, reported similar behavior to S. indica var. parviflora from native species too, noting that Scutellaria nervosa (native to the Mid-Atlantic with rare presence in Georgia) and Scutellaria incana are always popping up in nearby pots. So this is a plant to use with consideration for its mint-like nature with careful siting. All this said, I am a fan!

 

Contributed by Liane Schleifer

 

* BONAP is a great resource for determining whether a plant is truly native on a local level (since plants don't understand geopolitical borders like states or "Southeast" etc. Click on the link, then look up a Genus. You will see maps for species. Understanding the Map Color Key is critical, so do review that first. Dark green just means there is some native presence somewhere in the state. Light green indicates where actual native presence is confirmed. For Scutellaria in particular: BONAP for Scutellaria