Blue Mistflower – An Aggressive Native With A Purpose


Blue Mistflower Conoclinium coelestinum

One of the more aggressive native flowers that has potential to be used in landscaping is the Blue Mistflower. This beautiful little gem holds an underground secret though…..rhizomes! Rhizomes are underground root/stems that spread out from the plant and send up new shoots. And while many rhizome plants are clump forming, this one will reach far and wide.

When it comes to native plants for landscaping, one would naturally be tempted to grow the Blue Mistflower based upon beauty alone. However, it’s spreading nature make this plant better suited to a border or wild area. That being said, there are strategies one can employ to try to contain it. And it has been helpful to me personally in my fight against the invasive Japanese Stiltgrass. So, file this info in the back of your mind, and if you happen upon someone who is trying to naturalize and restore an area, consider suggesting this plant. In the right place, it can make a beautiful sight that also benefits our pollinators.

Scientifically known as Conoclinium coelestinum, the Blue Mistflower will grow 1-3′ tall in full sun and moist to mesic well-draining soil in Southeastern North America. Blooming clusters of blue-lavender flowers for a month in late Summer to Autumn, it attracts dozens of species of bees and butterflies[1][2][3].

Blue Mistflower Conoclinium coelestinum

Many gardeners are afraid of using this plant in a formal flowerbed, and I must say I am one of them. That doesn’t stop me from growing it in wild areas though, as I am currently using it in my fight against Japanese Stiltgrass. I must say that it is spreading out and holding it’s own, actually more than it’s own as it is slowly spreading along the border for a forest that is behind my home. However, there are some strategies one could employ to keep this little monster contained that I will share later in this article.

But this will be a complete profile on this late-blooming perennial, including the following:

Native Range

The primary native range of the Blue Mistflower is the Southeastern United States, from Texas to Nebraska, East to New Jersey and Florida.

Blue Mistflower native range

Reference Table

Scientific NameConoclinium coelestinum
Common Name(s)Blue Mistflower
Native Range, USDA ZoneCentral and Eastern North America, USDA hardiness zones 5-10
Bloom TimeLater summer and fall
Bloom Duration, Color4-8 weeks, Blue to lavender
Height1.5-3′
Spacing / Spread1.5-3′
Light RequirementsFull sun to part-shade
Soil TypesSandy loam to clay loam
MoistureSlightly moist to slightly dry
Fauna Associations / Larval HostsBees, butterflies / hosts several moth caterpillars

Pros and Cons

Pros

Beauty

The small clusters of pastel-shaded flowers are beautiful when densely planted or when examined up close. The contrast with the green foliage looks really nice./

Wildlife

This plant serves dozens of species of insect, from bees and butterflies who want pollen and nectar to caterpillars who feed on the foliage.

Groundcover

In the right setting, this plant’s hyper-aggressive nature is a feature. It can cover a lot of ground in a hurry. It’s rhizomatous nature is evident in it’s first year, and this allows it to compete with taller plants. The Blue Mistflower has a naturalizing ability that is above most other species.

Late season nectar

This is a late blooming flower. For me in zone 6/7 it normally blooms in late August into October, which puts it in the same class as other really late bloomers like Maximilian Sunflower and Aromatic Aster. The late bloom time means that it will have nectar available for late season pollinators as well as migrating Monarch Butterflies.

Cons

Aggressive

While Blue Mistflower’s hyper-aggressive nature is an asset in wild areas, it can be a bad thing in formal, mulched flower beds. In no time at all this plant will be popping up all over the place. You will need to stay on top of it by digging up unwanted shoots in the Spring, or attempting other methods to slow/stop the spread. You may wish read my ‘how-to‘ on doing this, as I have had it work with other rhizome-plants like Bee Balm and Obedient Plant.

Identification and Characteristics

Blue Mistflower identification

Stalk

A shorter perennial, Blue Mistflower grows up to 2-1/2 feet tall on a round, light green to red stem with small white hairs. It is irregular in it’s branching in that it could be little to much. Now, in general this plant is erect, but in nitrogen rich or fertile soils it may flop over. If it does, and the stem contacts the ground it can sprout new roots.

Leaf

Leaves are opposite, ovate to oval-cordate in shape with dentate margins, and 2-3″ wide by 1.5-2″ wide. They are light green and veined, and resemble leaves of White Snake Root.

Blue Mistflower leaves stalk

Flower

At the and of the stems will be clusters of flowerheads (corymbs) that are 1-3″ diameter & flat-topped. Each individual flowerhead will have around 40-90 florets that range from blue to purple or pink[3].

Blue Mistflower floret

How to save seed

Approximately 6 weeks after blooming the flowerheads will change to fuzzy seedheads. Each individual floret will be replaced with a single seed that has a small feather/tuft attached.

When they begin to turn dry, cut the seed heads and place into a brown paper bag. Place this bag into a cool dry place for a week (like a garage). Remove the seed by shaking the bag and store it in a sealed container, in the fridge until you are ready to sow it.

Root

The root system is fibrous and produces many rhizomes. This is a very aggressive plant!

Blue Mistflower rhizome roots
The thick white roots are actually rhizomes. This plant germinated in April, and this image was taken in October when I transplanted it to it’s final location.

Is the Blue Mistflower invasive?

Within it’s native range, no plant can be invasive. It can be very aggressive though, as I have eluded to throughout this article. But, in disturbed or open areas that are slightly moist with lots of sun, the Blue Mistflower can be very aggressive. The rhizomes were already spreading six months after I germinated my first seeds, and I would be a liar if I didn’t say I had second thoughts as I was planting it in my wild areas. I had read plenty of horror stories on this plant and how aggressive it can be. After several years, I can say that it isn’t too aggressive in areas with lots of competition.

Lookalikes

Below I will tell you how to differentiate some common lookalikes from Blue Mistflower.

Boneset (Eupatorium perfoliatum)

Boneset

Boneset likes similar growing conditions, and the flower structure is very similar. However Boneset has white flowers and it’s leaves are more narrow (lanceolate) in shape.

*Late boneset is also a lookalike, but prefers much drier areas and is much bushier.

Pink Thoroughwort (Fleischmannia incarnata)

Possibly the most difficult to differentiate, Pink Thoroughwort differs from Blue Mistflower primarily in that Blue Mistflower often had a reddish or purple stem later in the season. Unfortunately the leaf size and flower structure sizes overlap considerably, making it difficult to tell them apart.

White Snakeroot (Ageratina altissima)

White Snakeroot

White Snakeroot is a white flowering native in the mint family that looks quite similar. But, outside of the flower color, the leaves of White Snakeroot narrow more to a tip, and the margin serrations are fine pointed, not dentate. Below you will find a side-by-side leaf comparison of White Snakeroot and Blue Mistflower leaves.

Compare leaves White Snakeroot & Blue Mistflower

Praxelis clematidea

A South American exotic that is becoming invasive in Florida, Praxelis looks very similar to Blue Mistflower. However, the stems of Praxelis are covered in long white conspicuous hairs[4]. The hairs on Blue Mistflower stems are sparse and small.

Joe Pye Weed

Joe Pye Weed

It almost isn’t worth mentioning Joe Pye Weed as a lookalike, but since some Plant Identification Apps are terrible at their job I may as well say something. First, Joe Pye Weed has whorled leaves, not opposite. The color of Joe Pye Weed flowers is often pink to reddish or white. And finally, Joe Pye Weed is generally upwards of 4-8′ tall, so not a shorter groundcover!

Growing Conditions

The preferred growing conditions of Blue Mistflower is full sun to part-sun, moist to medium-moist soil (but it can tolerate slightly dry). It can grow in sandy loam to clay loam, but cannot tolerate drought. So, if it is sandy loam, make sure there is either plenty of organic matter or that the drainage is somewhat poor to help retain moisture.

How to Grow Blue Mistflower from Seed

Blue Mistflower is easy enough to grow from seed, but it does have a dormancy mechanism that must be overcome with cold-moist stratification. So, you should either winter sow the seed or cold-moist stratify it in the fridge, in a paper towel for at least 21 days[2][5].

Blue Mistflower seeds

For planting depth (of stratified seed, or winter sowing) the seed should be pressed into the surface of the soil. Do not bury the seed as it needs exposure to light to germinate.

Place the container in a location that receives morning sun and afternoon shade, and only water in the morning by misting. The seed should germinate when daytime temperatures approach 60F for a couple weeks.

Blue Mistflower seedlings
Blue Mistflower seedlings that I germinated.

Wildlife, Pests, and Diseases

Pollinators

Blue Mistflower is an incredibly important pollinator plant, and has been documented attracting upwards of 80 unique species. These include long-tongued bees, short-tongued bees, beetles, butterflies, moths, pollinating flies, and wasps. Several moth caterpillars will also feed on the foliage.

Deer and Rabbits

As a member of the mint family, deer and rabbits will not eat this plant because of the strong taste of it’s foliage.

Disease

Blue Mistflower will generally be disease free.

Where you can buy Blue Mistflower

is not typically sold in nurseries, as it isn’t a typical ‘garden friendly’ plant. 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.)

Landscaping

If one wishes to landscape with Blue Mistflower, you have to either have a plan to deal with the spreading nature of it, or just plant it in a wild area and let it do it’s thing. The fact is, this plant is just as aggressive as people say! Again, here is my guide to containing rhizome plants in the garden, and yes, it has worked well for me.

But the better option is to let this plant run wild in a border garden, slope, or wild area where it can compete. I have this in the forest behind my home where it is actively competing with, and beating, Japanese Stiltgrass. It is a slow fight, as the Stiltgrass is so prevalent, but I am slowly retaking ground ground.

Blue Mistflower Japanese Stiltgrass
This image shows Blue Mistflower growing amongst Japanese Stiltgrass (and some Black Raspberry too). It is slowly spreading and capturing land in it’s conquest (the Mistflower that is).

Companion Plants

For some companion plants that will grow well with Blue Mistflower, see the table below:

Spring BloomsSummer BloomsFallGrass
ColumbineEchinaceaCommon BonesetBottlebrush Grass
Virginia BluebellsHairy Wood MintShort’s AsterLittle Bluestem
Bee BalmMountain MintSweet GoldenrodPrairie Dropseed
VioletsObedient PlantVarious sedges

Final Thoughts

This aggressive little native beauty has the potential to take over small gardens in a short time period. But, in the proper setting with other competition, it should be held in check (somewhat). That being said, keep this flower regulated to the more wild parts of your yard, or where you could easily remove or mow unwanted plants and you should be good to go.

Find more native plants here

References:

[1] – Conoclinium coelestinum (L.) DC., USDA NRCS.

[2] – Whitten, Jamie L. BLUE MISTFLOWER Conoclinium coelestinum (L.) DC. USDA Plant Fact Sheet, NRCS. 2002. Accessed 10JAN2025

[3] – Wooten, Jean W., and André F. Clewell. “Fleischmannia and Conoclinium (Compositae, Eupatorieae) in eastern North America.” Rhodora 73.796 (1971): 566-574.

[4] – Khamare, Yuvraj, et al. “Biology and Management of Praxelis (Praxelis clematidea) in Ornamental Crop Production: ENH1321/EP585, 8/2020.” EDIS 2020.4 (2020).

[5] – Vandevender, John. “Propagation protocol for production of container Conoclinium coelestinum (L.) DC. plants (1+ 0 container plug).” Natural Resources Conservation Service-Appalachian Plant Materials Center, Alderson, West Virginia. In: Native Plant Network. URL: http://www. nativeplantnetwork. org (accessed 6 March 2014). Moscow (ID): University of Idaho, College of Natural Resources, Forest Research Nursery (2014).

Joe Foster

Hi - I grew up outdoors in nature - hiking, fishing, hunting. In high school I got my first job at a garden center where I learned to garden and landscape. I've been growing plants from seed and designing native plant gardens for over 10 years. I hope to share some of my knowledge with you! You may have seen some of my videos I create on our YouTube channel, GrowitBuildit (more than 10 million views!). You can find my channel here: https://youtube.com/@growitbuildit Additionally I am a wood worker / DIY enthusiast. I enjoy designing/building projects (with hand tools when I can!). I hope to give you some tips and useful information!

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