Aromatic Aster is a herbaceous perennial native to North America. Scientifically known as Symphyotrichum oblongifolium, it grows 2-3′ tall by 2-3′ wide in full sun and dry to medium-moist soil. One of the last flowers to bloom before Winter, it’s numerous purple daisy-like flowers attract numerous pollinators and it hosts several caterpillars.[1][2][3]
I’ve been growing Aromatic Aster in my gardens in some capacity since about 2016, and always love the late-season color when all my other neighbor’s gardens have been put to bed for the year. This article will be a fully comprehensive guide to this plant from germinating seed to winter care.
In this article:
- What is Aromatic Aster
- What are the pros and cons of Aromatic Aster
- Identification / Characteristics
- How to grow and care for Aromatic Aster
- What Wildlife, Pests, and Diseases effect Aromatic Aster
- Where to buy Aromatic Aster
- Uses of Aromatic Aster
- Final thoughts
What is Aromatic Aster
When it comes to late-flowering Perennials, Aromatic Aster is just about the last flower to bloom before Winter in North America. Getting it’s common name not from the flowers, but the aroma of the leaves when crushed, Aromatic Aster will give off a balsam or anise-like scent. The value this provides to pollinators that are still active is immense. In fact, I have a neighbor with some beehives up the street, and I almost feel like he should be giving me a free jar of honey because I’m the only house feeding his bees in October!
This is a tough rugged plant that will develop stiff stems by September and can grow in what would normally be considered inhospitable conditions. Somewhat tolerant of salt, and perfect for full sun and slopes, Aromatic Aster doesn’t get that tall, so may get shaded out in more moist environments.[2][4]
Now most references will state that it gets up to 3′ tall, which is true. But what you need to understand about Aromatic Aster is that will often arch over reducing it’s height to under 2′. Now, this is normally not a desirable trait in a flower – but this plant has another trick up it’s sleeve. You see, while most flowers have their flowers at the top of the stalk, Aromatic Aster will bloom along much of the stalk. This means that even if the plant arches over or flops, it is still going to make for a short clump of blue-lavender daisy like flowers.
One trait that must be considered before adding Aromatic Aster to your garden is aggressiveness. This plant has the capacity (and will) spread via seed and underground rhizome. You can mostly control this in early Spring when it emerges, just pulling unwanted seedlings or shoots. But by September you will probably notice a few flowering stalks that you missed. Overall, it is aggressive, but it is completely manageable.
Native Range of Aromatic Aster
The primary native range of Aromatic Aster is the Central United States from Texas to Wisconsin & North Dakota. Isolated but significant population occur in other states such as New York, North Carolina, and Pennsylvania.
Reference Table
| Scientific Name | Symphyotrichum oblongifolium |
| Common Name(s) | Aromatic Aster |
| Native Range, USDA Zone | North America, USDA Hardiness Zones 3-8 |
| Bloom Time | Autumn, September-November |
| Bloom Duration, Color | 4-8 weeks, blue, lavender, purple |
| Height | 2-3′ |
| Spacing / Spread | 1-3′ |
| Light Requirements | Full sun |
| Soil Types | All textures |
| Moisture | Dry to medium-moist, well-drained |
| Fauna Associations / Larval Hosts | Numerous bees, butterflies, skippers, bettles. Hosts the Silvery Checkerspot and various moths. |
What are the pros and cons of Aromatic Aster
Pros
Late Bloomer
Aromatic Aster is one of the last native perennials to flower before Winter. If you have this flower growing in a few strategic locations, you can keep your yard flowering through frosts and after leaves drop. And this will make your yard contrast nicely compared to most other suburban yards that normally have their flower gardens put to bed by Autumn.
Beauty
Aromatic Aster will produce numerous blooms all along the stalks and at the tops of the plants. This gives it a beautiful appearance from all angles. Even if it flops over, it will still make a showy flowering clump that is eye-catching.
Adaptable
Aromatic Aster has evolved to be able to grow in almost any soil texture as long as it can drain. This means that it can be planted almost anywhere that gets enough sunlight.
Wildlife
Due to Aromatic Aster blooming so late in the growing season, it is incredibly valuable to nectar seeking pollinators.[5] I like to think that the bees that visit my plants late in the year are ever thankful for the oasis of nectar my plants provide. And in my neighborhood, there is not much else blooming, as Aromatic Aster seems to outlast store-bought mums that every other house seems to have.
Cons
Aggressive
The biggest drawback to Aromatic Aster is that it is a bit aggressive in a formal flower bed. Now, don’t get me wrong, it is completely manageable in that you just need to pull unwanted shoots and rhizomes in the Spring. It does have the capacity to self-seed as well, but rhizomes are the primary manner in which it spreads.
Ugly foliage during drought
During very dry weather or late in the season, the lower foliage of Aromatic Aster will often turn brown and fall off. In dry years this can make the lower portion or center of the plant a bit unsightly.
Can sprawl
As Aromatic Aster grows and the stalks get longer, the stems will often arch and droop over to the ground. Now, when it comes to overall showiness this isn’t a problem because nearly the entire stalk will flower. But the center of the plant, in dry years may look a bit sparse.
Identification and Characteristics of Aromatic Aster
Stalk
The stalk of Aromatic Aster will branch frequently. Initially green, the stalk turns stiff and almost woody as it matures with the lower stems turning brown.
Leaf
Aromatic Aster has dense leaves that alternate up the stalk and are 2″ long by roughly 1/2″ wide, linear in shape, have few short hairs, and ciliate margins. The further you go up the stalk, the smaller the leaves will be. Near the inflorescence the leaves are quite small and narrow.[2]
Flower
For flowers, numerous compound daisy-like blooms will cover the plant. They are roughly 1″ diameter with 20-40 lavender to blue petals (ray florets). The central disc is actually small disc flowers that are yellow when young, turning to orange/brown as they age.[2]
About four weeks after blooming seeds (achenes) will form with small tufts of hair/feathers, similar to dandelions.
Saving seed from Aromatic Aster
To save seed from Aromatic Aster, just wait roughly one month after the flowers have finished blooming. Once the seed heads have turned fuzzy/hairy, you can collect the seeds. Simply pinch it directly off the seed head and place into a paper bag or container. Let the seed dry for a week in a cool dry place. Afterwards the seed can be stored in an envelope or sealed container for a couple years in a cool, dark, dry place.[2]
Root
The root system of Aromatic Aster consists of fibrous roots and rhizomes. Aromatic Aster is an aggressive perennial in formal flower beds, and will spread mostly by underground rhizomes if left unchecked.
Emerging in Spring
Sometimes we have trouble identifying perennials when emerging in Spring. So, I am adding a couple photos to show you what Aromatic Aster looks like when emerging from it’s long Winter slumber.
Video of Aromatic Aster
Below is a video we made on Aromatic Aster. It is fairly exhaustive, and contains quite a bit of interesting footage (much of it slow-motion) or pollinators. It also provides some examples of how to landscape with this wonderful plant. I hope you enjoy it!
Grow and Care for Aromatic Aster
Sunlight Requirements
For sunlight, Aromatic Aster will grow best and be it’s showiest in full sun, which is at least six hours of sunlight per day.[2][3]
Soil Requirements
For soil texture or soil type, Aromatic Aster is highly adaptable in that it can thrive in anything from shallow rocky soil to clay, as long as it drains well.[2][3]
Moisture Requirements
When it comes to moisture requirements Aromatic Aster does best in medium-moist soil. It can also be perfectly healthy in dry soil but the lower leaves may dry up and fall off.[2][3]
Maintenance
For maintenance, it can be cut back in Winter after blooming all the way to the ground. Although if you leave 6-12″ of stalk above ground, bees may nest in it during the following Spring.
If you are growing Aromatic Aster in a formal flower bed, you should plan on pulling up unwanted rhizome sprouts each Spring. For a single plant this can take 20-30 minutes depending on how many there are.
Fertilizer
Aromatic should not need supplemental fertilizer of any kind.
How to Grow Aromatic Aster from Seed
Aromatic Aster doesn’t have any special germination requirements. You can simply plant the seed on the surface of the soil and keep moist. Although I would strongly recommend you do this in Spring, and keep it in a location that receives morning sun and afternoon shade, as this will help keep the seed from drying out while still providing warmth.
If you are planning on planting other natives though, you could consider Winter Sowing Aromatic Aster along with your other species. It is incredibly simple, and you will get great germination rates. The image of seedlings below is from one of my milk-jugs I used to Winter Sow Aromatic Aster several years ago.
Direct sowing Aromatic Aster
Aromatic Aster can also be direct sown from Fall to Spring. Simply scatter the seeds over a disturbed (bare, roughed up) area. Then walk on the seeds to ensure they have good contact with the soil, but aren’t buried much.
Dividing Aromatic Aster
If you’ve read this entire article, and learned how much I’ve spoken about rhizomes and spread then it should be no surprise to you that division is a great way to propagate this plant. Aromatic Aster can be formally divided every 3-5 years. But in reality, if one wants to propagate new plants you only need to cut and plant the newly emerging shoots in Spring. If a stalk has at least a few roots, then planting it in the cool Spring soil is all that is needed to give birth to a new colonizing plant.
Controlling Aromatic Aster
I’ve spoken about the aggressive nature of Aromatic Aster, and now I will lay out the steps I take to maintain control of it each year. You see, Aromatic Aster will self-seed somewhat, so you should consider cutting it back in Winter for this reason. But, the main thing you need to do to control it’s spread happens in Spring.
Each Spring new flowering shoots will sprout up 6″-24″ from the central clump, and these should be pruned. You can pull them up, tracing their path back to the central stem to remove them. As stated above, any one of these can be planted in the ground or pot to begin a new plant. But, removing these in early Spring will contain the primary spread of the plant, leaving it confined in a formal flower bed to the location that you wish it to stay.
Wildlife, Pests, and Diseases associated with Aromatic Aster
Pollinators
As one of the last flowers to bloom, Aromatic Aster is quite popular with pollinators late in the season. Numerous bees (long and short tongue), butterflies, skippers, and moths all visit the flowers. And, several pollinator caterpillars will feed on the foliage such as the Silvery Checkerspot and various moths.
Birds
Turkeys and other birds will feed on the foliage of Aromatic Aster
Deer and Rabbits
For deer and rabbits, in my experience they will feed on young tender foliage. But they tend to avoid mature specimens, most likely due to the tough stems.
Disease
Aromatic Aster is not bothered by disease.
Where you can buy Aromatic Aster
True Aromatic Aster is not typically sold in nurseries, as it isn’t a typical ‘garden friendly’ plant. Although you may see it listed in big-box stores as ‘Aromatic Aster’, this is most often a hybrid or cultivar that was created via cross breeding with other Asters. These hybrids are often taller than Aromatic Aster with larger leaves.
But, the straight native can often be purchased at specialty nurseries that deal in Native Plants. You can find native plant nurseries near you on our interactive map.
Varieties of Aromatic Aster
Due to it’s showiness, ruggedness, and late-flowering, several varieties of Aromatic Aster have been developed by the nursery industry.[6]
- Symphyotrichum oblongifolium ‘Fanny’s Aster’ – a selected variety from South Carolina that is a bit shorter (2′ tall) clump that grows up to 8′ long, with blue flowers that begin flowering in October in NC.
- Symphyotrichum oblongifolium ‘October Skies’ – a bushier and less aggressive form of Aromatic Aster.
- Symphyotrichum oblongifolium ‘Raydon’s Favorite’ – A selection that is extraordinarily showy.
- Symphyotrichum oblongifolium var. angustatus
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 Aromatic Aster
Garden Uses
Aromatic Aster makes a great addition to a short border garden, meadow, micro-prairie, and wildflower garden. It can also be grown in isolation in formal mulched flowerbeds as long as it is pruned in Spring by pulling unwanted sprouts. It can also be used almost as a ground cover in that it will spread if given room.
Know that it is possible for it to flop over, but as long as this happens by July, it will still look showy as the flowerheads will form a natural ‘wall’ of flowers that cover the entire outer shape. This is because the flowers occur all along the stalk, and not just at the end!
One other thing to note is that if allowed to completely grow without competition, and if it receives sun from all sides, it will basically form a hemisphere. When it forms this shape, it is usually quite attractive and showy in Autumn. If you approach it though, you may notice that the center doesn’t have as many flowers as it has just sprawled in all direction to maximize the sunlight it can collect.
Companion Plants
For companion plants to Aromatic Aster, try other dry to medium-moist, full-sun loving native perennials. Some possibilities include the following:
- Dotted Blazing Star
- Echinacea paradoxa
- Frost Aster
- Hairy Beardtongue
- Hoary Vervain
- Narrow Leaf Coneflower
- Perennial Black-Eyed Susan
- Rattlesnake Master
- Sideoats Grama
- Spotted Beebalm
- Tennessee Coneflower
Medicinal Uses
The only medicinal use of Aromatic Aster I could locate was a couple of old Native American uses. They created a lotion from a decoction to use as a protection from witches and also for treating fevers.[2][7]
Final Thoughts
If you are looking to maximize your blooming season in a given year, then Aromatic Aster is probably one the best choices you could make considering how late it blooms into the season. Considering all the species of flowers I grow, Aromatic Aster is just about the latest blooms I have. In fact while all my neighbors flowers have died off for Winter, I will still have pollinators. And I even think that I am responsible for keeping my neighbor’s honeybees alive!
There are a few drawbacks to Aromatic Aster (as I’ve noted), but these are generally manageble. But if planted in a suitable location, you can bet that Aromatic Aster will look great for you, and show up all your neighbors by still producing flowers into Fall.
Find more native plants here
References:
[1] – Symphyotrichum oblongifolium (Nutt.) G.L. Nesom, USDA NRCS. Accessed 20OCT2023.
[2] – Shawn Belt, Aromatic Aster Plant Fact Sheet. USDA NRCS, National Plant Materials Center, Beltsville, MD, 2009
[3] – Picton, Paul, The plant lover’s guide to asters, Portland, Oregon : Timber Press, pp251, 2015
[4] – Sun, Youping, et al. “Salt Tolerance of Ten Perennial Plants in Asteraceae.” Utah State University, 2015.
[5] – Calles-Torrez, Veronica, et al. Pollinator Preferences for Selected Aster, False Indigo, Bee Balm, and Sedum Flowers in North Dakota. NDSU Extension, North Dakota State University, 2020. Accessed 27OCT2023
[6] – Hawke, Richard G., A Comparative Study of Cultivated Asters. Chicago Botanic Garden, Plant Evaluation Notes, Issue 36, 2013.
[7] – Symphyotrichum oblongifolium, North American Ethnobotany Database. Accessed 27OCT2023.
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