Hoary Vervain is a herbaceous, short-lived perennial that is native to central North America. Scientifically known as Verbena stricta, it grows to 2-4′ tall in full sun and well draining soil, it flourishes in medium to dry conditions. Blooming purple flowers at least six weeks in summer, it attracts numerous species of bee, butterfly and moth[1][2].
I first noticed this flower along the edge of a sandy farm field some years back and figured I would try growing it based on how much I love it’s cousin, Blue Vervain. I must say though, Hoary Vervain is showier as it’s petals are larger giving a nice appearance. It’s long bloom time, showiness and the amount of pollinators it attracts are amazing, making this plant really stand out.
And I was quite taken with this plant on a summer road trip to the Badlands where I frequently saw Hoary Vervain blooming along the roadsides. It added a nice splash of color contrasting with the white and red landscape.
I first grew several specimens of this in a flowerbed that is on an inhospitable mound and fully exposed to the elements. It often gets dry/drought conditions, but Hoary Vervain seemed to thrive.
Facts
- Long bloom time – A single plant will often bloom for six weeks in Summer
- Drought tolerant – This plant can survive in arid conditions. I personally noticed a large number of them visiting Badlands National Park. And I’ve also seen it growing in sandy soil near small rivers in the midwest.
- Extremely popular with pollinators. Over 120 species have been recorded visiting
- Deer and rabbit resistant – the strong tasting foliage (similar to other members of the Verbena genus) keep most herbivories away.
Native Range
The primary native range of Hoary Vervain is from Wyoming, East to Ohio, and from North Texas to Manitoba. Due to its beauty though, it has been naturalized in other states in the Northeast[3], Southeast as well as Nevada, Arizona, and Idaho[1][2].
Reference Table
| Scientific Name | Verbena stricta |
| Common Name(s) | Hoary Vervain |
| Native Range, USDA Zone | Central North America, USDA hardiness zones 4-7 |
| Bloom Time | Summer |
| Bloom Duration, Color | 12 weeks, purple |
| Height | 1-3′ tall |
| Spacing / Spread | 18-24″ |
| Light Requirements | Full sun |
| Soil Types | Sandy to Clay loam. Must drain well. |
| Moisture | Dry to medium-moisture |
| Fauna Associations / Larval Hosts | Over 100 species of pollinators. / Hosts several moth caterpillars. |
Benefits
Beauty
This plant makes beautiful purple flowers that are attractive in mass plantings. It can also act as a nice background flower to showcase other species in formal flower beds.
Long Bloom Time
This is one of the longest blooming flowers I’ve grown. I had blooms beginning in July and continuing through Mid-August. And this is inline with what most references state.
Pollinators
With over 100 species of bee, butterfly, and moth visiting – Hoary Vervain is a pollinator powerhouse. It really brings in a large variety of species who seek nectar and pollen[4].
Drought tolerant
One of the more drought tolerant flowers that also grows well in temperate climate, Hoary Vervain is tough. I’ve seen it growing well in the Badlands of South Dakota, which is one of the drier areas in the USA.
If you need even more convincing, in 2012 a study was done growing native plants on a sloped roof in Illinois in just 4″ of soil[5]. Hoary Vervain survived and increased it’s population for the duration of the study (5 years). It should be noted that after year one, they did not water anything. All the plants had to survive on rain water.
Thrives in poor soil
This is one of those flowers that seems to thrive in poor, crappy soil. It doesn’t care if there isn’t any organic matter, it will grow just fine. So if you are converting an old lawn into a flower garden, this plant would be a great choice!
Identification and Characteristics
While generally easy to identify, know that Hoary Vervain, like nearly all members of the Verbena genus readily hybridizes with other vervains[6]. So, take care when identifying to make sure you’ve got it right!
Stalk
The stalk of Hoary Vervain is generally covered in white hairs and light green in color but can turn a red color as well. There will often be branching in the upper third of the plant.
Leaf
The leaves are opposite along the stalk with no stem, oval to ovate in shape and coarsely serrated. They are white-green in color and have white hairs, which contribute to the color[2].
Flower
As the stems rise, the upper portion will be spikes of flowers. In general they are 2-10” long and densely covered in flowers that bloom starting blooming from the bottom, working their way to the top over a period of roughly six weeks in summer. Individual flowers are small, usually ¼” diameter (6 mm) with 5 spreading lobes (petals) that are pink to lavender in color[2]. Occasionally flowers can be completely white[7].
Flowers can self pollinate, but are also readily pollinated by specialty bees as well as the many butterflies that visit[8].
How to save seed
To save seed, wait about a month after the flower has finished blooming and has turned brown. This usually occurs by October. With a container or brown paper bag and scissors, cut the brown & dried seed heads off and carefully place into the container. The seed easily falls from the stalk, so if it is bumped or jostled you will lose some.
Place this container in a cool dry, dark place for a week to let it fully dry. Then, simply shake the bag or container (not violently). The seed will easily separate. You can store fully dried seed in an envelope or plastic bag for a couple years in a cool, dark place.
Root
The root system consists primarily of a taproot and fibrous roots[2]. But it doesn’t need deep soil to thrive. In case you skipped it from above, I cited a study done in Illinois in 2012 that had Hoary Vervain surviving (and increasing numbers) over a 5 year period with only rain water[5].
Growing conditions
Hoary Vervain prefers full sun and dry to medium-moist soil. For soil texture, it does best in sandy, sandy-loam, clay loam, or loam[2]. It does best in poor soils, as it can out-compete most other plants. However in richer soils with organic matter it is often shaded out by taller native plants.
Maintenance
There is no special maintenance required for Hoary Vervain. It may self-seed, which may necessitate pulling unwanted seedlings, but that is about all. If you don’t want any self-seeding, simply dead head the blooms at the end of their blooming period before the seed heads dry out.
Fertilizer
You will not need to fertilize Hoary Vervain! It will do absolutely great in poor inorganic soils.
How to grow from seed
It isn’t too hard to grow Hoary Vervain from seed. It does need a cold stratification period of sixty days to break dormancy[9]. You can accomplish this by cold stratifying in the fridge or winter sowing. Additionally, the seeds also need exposure to sunlight to break dormancy, so make sure they are on top of the soil.
But to germinate the seeds, I personally find winter sowing the easiest way to do so. See my detailed guide on winter sowing here. But firmly fill a suitable container with moist potting soil and scatter some seed on top. Then press it firmly into the soil with your thumb but make sure you don’t bury the seed. Place the container in a location that gets morning sun and afternoon shade. Germination will occur once temperatures warm up in the Spring.
Establishment
Once seedlings develop 2-3 sets of true leaves you can either separate and pot-up the seedlings to larger pots, or you can transplant to it’s final location.
To plant seedlings into their final location simply dig a hole to the same depth the plant is currently at, then stab your trowel or garden shovel a few more times to loosen the dirt just a bit. Then, fill the hole with water and let it drain two times (this provides a small water supply to the plant). Finally plant your seedling.
Wildlife, Pests, and Diseases
Pollinators
Numerous pollinators are attracted to the flowers, primarily for the nectar produced. Charles Robinson observed over 120 different species of long-tongue bee, short-tongued bee, butterfly, moth, and pollinating fly in his amazing 1929 survey[4]. Several specialty bees also visit for pollen[2].
I personally dozens of different pollinators visiting my plants throughout the long blooming period. If you grow at least 3-4 plants, you will likely have huge numbers of pollinators too.
Beyond pollination though Hoary Vervain hosts several moth caterpillars and some other insects feed on the foliage such as grasshoppers. Specifically it hosts the Fine Lined Sallow Moth (Catabena lineolata) and the Verbena Moth (Crambodes talidiformis)[2].
Birds
Songbirds feed on seeds during the winter. You can find the birds milling around on the ground in early winter picking out seeds that fell[2].
Deer and Rabbits
Deer and rabbits generally avoid eating any species of Verbena as the foliage has a strong flavor. I have not seen any damage to my plants.
Disease
Hoary Vervain is nearly disease free. I’ve never seen about, nor heard about any disease harming it as long as it is planted in full sun and well draining soil. Poorly draining soil could be an issue, as it’s tap root could be prone to root rot.
Where you can buy Hoary Vervain
Hoary Vervain is not typically sold in nurseries, as it isn’t considered flower-bed friendly by the landscape industry. But it can be purchased at specialty nurseries that deal in Native Plants. You can find native plant nurseries near you on our interactive map.
Where to buy seeds
We have ordered a variety of native flower seeds from Everwilde Farms, which you can order right from Amazon through our link on our RECOMMENDED PRODUCTS PAGE. (We may earn a small commission when you purchase through our links, at no cost to you. This helps support our website.)
Uses of Hoary Vervain
Garden Uses
Hoary Vervain can be used in medium to dry wildflower areas, native plant gardens, hellstrips, or microprairies that drain well. The key is that it can’t get shaded out by taller plants that usually occur in more moist environments. Dry, drought prone and well-draining areas rarely have vegetation that can out-compete shorter plants.
It’s long bloom time make it attractive for long periods of summer and bring in lots of wildlife interest. But it isn’t so aggressive, so keeping it in a formal flower bed works too, as you an see in the image below (my ‘mound’ garden in my front yard). Plant at least 3 or more plants to attract more pollinators, as they like an ‘all-you-can-eat’ buffet!
Companion Plants
Hoary Vervain grows well with other plants and grasses that also like dry to medium-moist conditions and full sun. Some nice companion plants that would blend well are listed below:
- Anise Hyssop
- Aromatic Aster
- Black Eyed Susan
- Blanket Flower
- Butterfly Weed
- Mexican Hat Coneflower
- Narrow Leaf Coneflower
- Tennessee Coneflower
- Spotted Bee Balm
- Wild Bergamot
- Buffalo Grass
- Little Bluestem
- Side Oats Grama
Medicinal Uses
It is reported that Native American used the leaves by boiling, then steeped to make a tea that treats stomach pains / gastrointestinal issues[10]. The flowerheads can also be used as an emetic[9].
Final Thoughts
When if comes to log-blooming flowers, Hoary Vervain is one of the longest lasting. While an individual spike isn’t overly showy, as only a few flowers bloom at a time, the duration makes it worth it. But you can make a showy display by growing multiple plants.
It’s ability to thrive in hot, dry soils that are poor or inorganic give it even more added value.
Find more native plants here
References:
[1] – Verbena stricta. USDA NRCS. Accessed 01FEB2024
[2] – Holm, Heather; Pollinators of native plants : attract, observe and identify pollinators and beneficial insects with native plants, Minnetonka, MN : Pollination Press LLC, 2014, pp307
[3] – Sanford, S. N. F. “The Occurrence of Verbena stricta and Helianthus mollis in Massachusetts.” Rhodora 6.65 (1904): 88-89.
[4] – Robertson, Charles. “Flowers and insects; lists of visitors of four hundred and fifty-three flowers.” (1928).
[5] – Armstrong, Patricia K. “Survival of plants on sloped roofs with ten cm of soil.” Erigenia: Journal of the Southern Illinois Native Plant Society 25 (2012). Retrieved 02FEB2024. Archived version.
[6] – Barber, Susan C. “Taxonomic studies in the Verbena stricta complex (Verbenaceae).” Systematic Botany (1982): 433-456.
[7] – Milligan, J. M. “Pure White Verbena stricta.” Botanical Gazette 2.12 (1877): 144-144.
[8] – Cruden, Robert W., et al. “The mating systems and pollination biology of three species of Verbena (Verbenaceae).” Journal of the Iowa Academy of Science: JIAS 97.4 (1990): 178-183.
[9] – Blake, Abigail Kincaid. “Viability and germination of seeds and early life history of prairie plants.” Ecological monographs 5.4 (1935): 408-460.
[10] – Fielder, Mildred, Plant medicine and folklore, New York : Winchester Press, 1975, pp271.
[11] – Verbena stricta, North American Ethnobotany Database. Accessed 20JAN2024
Recent Posts
One of the more common 'types' of plants to grace North America, but get almost no interest from gardeners is Wild Lettuce. You are likely to have encountered one of these plants whether hiking,...
Culver's Root is a perennial Wildflower native to North America. Scientifically known as Veronicastrum virginicum, it typically grows 3-5' tall in full sun and moist to medium-moist soil. Blooming...