Great Blue Lobelia for New Gardeners: Easy Seed-to-Showtime Tips

Q: Is great blue lobelia poisonous?

Yes. It’s less likely to kill you than other poisons you might come across in the North American wilderness, such as water hemlock (Cicuta maculata or C. douglasii) or white snakeroot (Ageratina altissima), but it still has some unsettling side effects. Great blue lobelia’s poisonous compounds include lobeline and lobelamine, which are toxic alkaloids related to nicotine. Symptoms of an overdose include nausea, vomiting, and heart problems. There are many native plants you can eat, but great blue lobelia is not one of them. However, this plant is still beautiful, and provides a food source for other creatures in your garden. Just don’t put it in your mouth, and maybe avoid planting it somewhere children or pets might be tempted to do so.

Q: Does great blue lobelia like sun or shade?

Great blue lobelia does best in the sun. It can handle some dappled sunlight, but too much shade will keep it from living its best life. It may get elongated and leggy as it searches for more light, and it likely won’t flower.

Q: Does great blue lobelia spread?

Yes. If you’re looking for a plant that is well-behaved and stays put, this isn’t it. Great blue lobelia aggressively self-seeds, and it can end with you having to pull up a bunch of volunteer seedlings that have colonized your garden beds.

Q: Will great blue lobelia come back every year?

Yes. Great blue lobelia is a perennial, which means it lives for multiple years. It will die back to the ground in winter, but don’t worry. Come spring, it will pop back up again to bring life to your garden once again. Great blue lobelia is a short-lived perennial, so you may not have the same plant for decades to come. However, its habit of readily self-seeding means there will be plenty of new sprouts to take its place, giving you a patch of lobelia that lasts much longer.

Highlights

This tall, stately native flower stands with a light saber of blue flowers in the summer. Butterflies and hummingbirds both love this plant. Great blue lobelia is easy to plant from seed; seeds planted in the spring will flower later in the summer. They love wetter areas, making them perfect for rain gardens or areas that collect water after it rains. Read on for growing tips!

Great blue lobelia in spring, a star-shaped rosette of green leaves seen from above — Great blue lobelias look like verdant stars when seen from above

Great blue lobelia, several spikes of blue flowers in a group planting — Great blue lobelias look amazing when planted in groups

Is great blue lobelia right for my yard?

Plant it if…

You want something low maintenance. Great blue lobelia is a tough plant that won’t ask you for anything once you plant it. It will take care of itself.
You have poorly drained soil. Great blue lobelia thrives in wetter soil, so any spot in your yard that collects water is a good place to plant it.
You want to attract hummingbirds. The long, slender flowers are tailor-made for them, so great blue lobelia is perfect for a hummingbird garden.
You live in an urban area. A study published in 2025 suggests that great blue lobelia has a positive effect on urban biodiversity.
You want to provide for pollinators. Large-bodied bees, including the endangered rusty patched bumblebee, are key pollinators for great blue lobelia.

Skip it if…

Your area is prone to drought. Great blue lobelia is unfazed by a variety of garden conditions, but it will shrivel once the soil dries out.
You need a well-behaved plant. Great blue lobelia can aggressively self-seed, so be prepared to pull up a lot of shoots and seedlings if you want it to stay put.
You need a plant that handles shade. Great blue lobelia needs sun to live its best life, and shade will cause it to grow long and leggy without flowers.

Where is great blue lobelia native?

Native to 36 US states, Washington, D.C., and 1 Canadian province (Ontario)

Native range

Not native

Sources: NatureServe, Royal Botanic Gardens, Kew (World Checklist of Vascular Plants) and the USDA PLANTS Database, compiled by The Plant Native. How we map native ranges

Great blue lobelia is native across much of the eastern and central United States, from New England south to Georgia and Louisiana and west to Colorado and Wyoming. It is also native to Ontario. It grows in a variety of habitats, from swamps and wetlands to meadows and prairies: anywhere there is wet soil. You can see the state-by-state record at NatureServe Explorer.

Its tall mass of flowers allows many creatures to eat at once, like a crowded buffet.

Why great blue lobelia matters

The bluish-purple flowers of great blue lobelia first appear in the summer, rising to a height of 5 feet. These pastel colored pillars will stand tall for months, lasting until the fall. These months are not quiet, as great blue lobelia is alive with visits from pollinators. Butterflies and bumblebees will buzz and flutter about this plant, feasting on nectar from each tiny flower. Its tall mass of flowers allows many creatures to eat at once, like a crowded buffet. Not only is great blue lobelia a favorite of insects, but it is favored by hummingbirds as well.

Monarch butterfly on a spike of blue great blue lobelia flowers — A monarch stops for nectar on great blue lobelia

The variety of pollinators great blue lobelia can support is part of what makes it so important. Urban and agricultural developments have caused the loss of habitat for many pollinators, contributing heavily to their decline. However, a study published in Ecological Entomology found evidence that great blue lobelia may be able to help. The study, published in 2025, found that great blue lobelia had an increase in pollinator visits in more urbanized areas. If you live in an urban area, planting great blue lobelia may be critical in supporting your local pollinators.

Great blue lobelia also supports endangered pollinators

Many large-bodied bees, such as bumblebees, act as pollinators for great blue lobelia. One of these bees, the rusty patched bumblebee, has been listed as federally endangered since 2017. The rusty patched bumblebee (Bombus affinis) is a ground-nesting species of bumblebee that was once distributed across the eastern and central United States. It lives in a variety of habitats, from meadows and prairies to forest edges. It is also considered one of the first bumblebee species to emerge from hibernation, as well as one of the last to go dormant in the fall. However, in recent years, the rusty patched bumblebee has experienced a steep decline in population. Even before its classification as an endangered species by the US government in 2017, the IUCN listed it as critically endangered.

There are many threats to rusty patched bumblebees, such as invasive species. Rusty patched bumblebees require a diverse buffet of nectar and pollen sources. When non-native species escape cultivation, some can colonize large areas and outcompete native species. This matters because the loss of native species also means a loss of food for pollinators like the rusty patched bumblebee. While plants like dame’s rocket (Hesperis matronalis) or cornflower (Centaurea cyanus) may look like native meadow plants to us, many pollinators won’t recognize them as a food source. As these plants spread across the meadows and wooded edges of eastern North America, they leave nothing behind for rusty patched bumblebees to feed on.

As a generalist species, the rusty patched bumblebee does not rely on a single species of flower for food. In the spring, they often rely on spring ephemerals to feed them for the first few months of activity. However, when the spring ephemerals die back in the summer, they turn to other sources of nectar. This is where great blue lobelia comes in.

Great blue lobelia flowers from midsummer all the way to October, which is when the rusty patched bumblebee goes into hibernation for the winter. This is no coincidence. According to observations in 2012 by Dale F. Schweitzer, a now retired researcher specializing in pollinators, “the disappearance of bumble bees in the fall appears to be timed with the passing of native fall flowers.” When flowers like great blue lobelia finish their floral display, bumblebees know it’s time to go to sleep for the winter. Until then, great blue lobelia provides a food source for a variety of bumblebees, especially rusty patched bumblebees, for months.

While planting great blue lobelia won’t singlehandedly save the rusty patched bumblebee, it can provide them a food source to help slow their decline. If every neighborhood in the eastern and Midwestern United States had one or two patches of great blue lobelia, it would provide a critical food source for these bumblebees. With invasive species and habitat loss pressing in, planting native flowers keeps the buffet open.

Where great blue lobelia shines in your yard

Rain garden: Great blue lobelia loves moisture, so it makes a perfect choice for a colorful rain garden.
Butterfly or pollinator gardens: Pollinators love great blue lobelia, from bees to butterflies. Pairing it with other pollinator-friendly plants can create a lively garden.
Meadows: Planting in a meadow can give great blue lobelia the light it needs to thrive, making it a great low maintenance spot.
Woodland garden: While full sun is ideal, dappled sunlight is also an acceptable light level for great blue lobelia. Plant it at the border of a woodland garden to provide a pop of color.
Near streams or pond edges: In the wild, great blue lobelia can be found on the banks of streams and in wetlands, so planting it near bodies of water will make it feel at home.

How to grow great blue lobelia

Where to plant

If you have a soggy spot in your garden you’ve been struggling to fill, great blue lobelia may be the plant for you. It only has two requirements: full sun and moist soil. Dappled sunlight is also acceptable, but sunlight is a must. The sun is what fuels the beautiful summer floral display. As for the water levels, consistent moisture is important. Otherwise, as long as it doesn’t dry out completely, great blue lobelia is happy with any spot you choose.

Great blue lobelia loves to live in wet areas. Rain gardens, areas where water frequently pools, or even nearby gutter downspouts are all great places to plant great blue lobelia.

When to plant

Fall seeding is an effective method of establishing great blue lobelia in a new area. However, if you want to replant it in other areas, you can divide it in spring.

Spacing

The USDA plant guide for great blue lobelia recommends spacing plants 8–12 inches apart. Since this plant self-seeds readily, it will fill in the space without you needing to do any extra work.

Watering

When you first plant great blue lobelia, give it a deep drink of water to help it establish. After that, it will subsist off of rainfall without a problem. However, if the occasional period of drought occurs, you can give it a little water to prevent it from drying out.

Growing from seed

Great blue lobelia is exceptionally easy to grow from seed. Most of the time, great blue lobelia will flower the first year it’s planted from seed.

Beginner tip

You may already be familiar with the fact that you can divide plants like hostas, but you can also divide great blue lobelia. If a clump gets too big, or you want to plant another somewhere else, you can divide it by removing the little offshoots at the base of the stem. You can remove them from the mother plant with a few roots and replant them. When dividing, replant immediately and water the new plant in its new location.

If you have the space, great blue lobelias shine when planted in groups. To plant great blue lobelia from a friend or neighbor’s garden…

In the fall, grab one of the tall stalks when the flowers have turned to seed
In your garden, lay the stalk down, stem and all, in the fall/winter
Cover very lightly with soil (Great blue lobelias need sunlight to grow, so don’t plant them too deep!)
In the spring you’ll see the tiny seedlings emerge
Planting the entire stalk ensures you’ll have a small patch of great blue lobelias
Make sure they stay consistently moist as they grow

Planting card

Great Blue Lobelia

Lobelia siphilitica

Full

Part

Shade

Moist to wet

3–5 ft tall1–1.5 ft wide

8–12 in apartTuck them in close for a full look

Some work

Every spring

Hummingbird fave Rain garden

What pairs well with great blue lobelia?

Great blue lobelia is a tough, self-seeding perennial that’s happy in wetter soils and attracts hummingbirds. As such, you can pair it with other plants pollinators love, or give it a viney backdrop with some of our climbing natives favored by hummingbirds.

Cardinal flower (Lobelia cardinalis): Another species from the same genus that can handle the same conditions. Plant them together for twice the color and hummingbird appeal.
Turtlehead (Chelone glabra): A wetland plant that grows in the same habitat as great blue lobelia, providing contrast in both color and height.
Joe Pye weed (Eutrochium fistulosum): Recommended by Mt. Cuba because it grows in similar conditions. It also attracts butterflies, adding to the pollinator party.
Buttonbush (Cephalanthus occidentalis): A moisture-loving shrub with little white flowers that look like pom-poms. Plant them together in a rain garden to attract pollinators, then watch as your backyard becomes a buffet of colorful customers.
Coral honeysuckle (Lonicera sempervirens): If you want a woody species to attract hummingbirds, coral honeysuckle can help. Plant it near a trellis or wall it can climb, plant great blue lobelia in front of it, and watch the hummingbirds dance around your garden.
Trumpet vine (Campsis radicans): Also called hummingbird vine, its beautiful reddish orange flowers attract hummingbirds as it climbs around your garden. It’s a vigorous grower, so it won’t get crowded out by great blue lobelia.

Where can I buy great blue lobelia?

There are many reputable places to buy great blue lobelia plants and seeds online, including:

Prairie Moon Nursery ($3 for a packet of seeds / $7 for a bare root plant)
Monticello: yes, that Monticello, Thomas Jefferson’s house! ($3.95 for a packet of seeds)
Seed Nerds ($1.99 for 100 seeds)

As you buy plants and seed, we have a tip:

Here are four ideas to find these native gems in your area:

Potential challenges with great blue lobelia

Aggressive self-seeding

Because it’s so easy to plant these from seed, they easily replant themselves in gardens. A plant that easily self-seeds and multiplies in gardens is often labeled as ‘aggressive.’ Some gardeners call great blue lobelia aggressive, but it’s easy to keep them in check.

To keep great blue lobelia plants from spreading, simply cut down the stalks in the fall and give them away to your neighbors and friends. That’s it! This will help cut down the amount of seed that spreads in your landscape.

Drought

Great blue lobelia can stand up to really any soil condition without breaking a sweat, but there’s one exception. Great blue lobelia will not handle drought. Its home is in wetlands and floodplains, not that dry, rocky strip near your driveway. To ensure a long life for your great blue lobelia, avoid planting it on slopes or places where water will drain away. That wet corner of your garden where nothing else survives? Try that instead. Nature will take care of the rest, but you may need to help out if you don’t get rain for a while.

Cardinal flower’s red spikes beside great blue lobelia’s blue flowers — Cardinal flower alongside some great blue lobelia

A note on cultivars and related species

Great blue lobelia has a red cousin: cardinal flower

If you’d like to put on a tall, stately flower show in the summer, consider planting some cardinal flower alongside your great blue lobelia. Cardinal flower is known as a particular hummingbird favorite.

Both are in the genus Lobelia, and you’ll see from a quick glance how similar their shape and flowers are.

Meet cardinal flower

FAQs

Is great blue lobelia poisonous?

Yes. It’s less likely to kill you than other poisons you might come across in the North American wilderness, such as water hemlock (Cicuta maculata or C. douglasii) or white snakeroot (Ageratina altissima), but it still has some unsettling side effects. Great blue lobelia’s poisonous compounds include lobeline and lobelamine, which are toxic alkaloids related to nicotine. Symptoms of an overdose include nausea, vomiting, and heart problems.

There are many native plants you can eat, but great blue lobelia is not one of them. However, this plant is still beautiful, and provides a food source for other creatures in your garden. Just don’t put it in your mouth, and maybe avoid planting it somewhere children or pets might be tempted to do so.

Does great blue lobelia like sun or shade?

Great blue lobelia does best in the sun. It can handle some dappled sunlight, but too much shade will keep it from living its best life. It may get elongated and leggy as it searches for more light, and it likely won’t flower.

Does great blue lobelia spread?

Yes. If you’re looking for a plant that is well-behaved and stays put, this isn’t it. Great blue lobelia aggressively self-seeds, and it can end with you having to pull up a bunch of volunteer seedlings that have colonized your garden beds.

Will great blue lobelia come back every year?

Yes. Great blue lobelia is a perennial, which means it lives for multiple years. It will die back to the ground in winter, but don’t worry. Come spring, it will pop back up again to bring life to your garden once again.

Great blue lobelia is a short-lived perennial, so you may not have the same plant for decades to come. However, its habit of readily self-seeding means there will be plenty of new sprouts to take its place, giving you a patch of lobelia that lasts much longer.

Do you deadhead great blue lobelia?

Great blue lobelia does not need to be deadheaded, as many native perennials will drop spent flowers on their own. However, deadheading can be helpful in controlling its self-seeding habits and encouraging more blooms.

Plant nerd fact

Is great blue lobelia a poison or a medicine?

The specific epithet, or species name, is rather unfortunate. The name siphilitica is related to the disease syphilis.

Although we can’t recommend eating great blue lobelia, there is some precedent for its use as medicine. Many Indigenous tribes used parts of it for various herbal remedies. As the scientific name suggests, syphilis was among the diseases great blue lobelia was used to treat. This historical usage of the plant was recorded in the 1818 Vegetable Materia Medica of the United States by William Barton. Additionally, tribes like the Cherokee also used it to treat headaches, coughs, and fevers, among other conditions, and they were certainly not alone.

However, the most unique use of great blue lobelia comes from the Meskwaki tribe, who used it in love medicine. In Huron Smith’s Ethnobotany of the Meskwaki Indians, he describes how the roots were used to end lovers’ quarrels. He calls it an “anti-divorce remedy,” saying, “Ground-up roots are secretly put into some common dish, which is eaten by both man and wife. The quarrel is soon over and they live happily together.”

Great blue lobelia is a beautiful native flower that attracts both butterflies and hummingbirds to gardens. Its natural blue color is rare in gardens, so it stands apart from other plants. It’s exceptionally easy to plant from seed and will flower the same year it’s planted. Plant them in groups to help them shine. They are a beautiful addition to any Mid-Atlantic, Midwest, Northeast, or southern garden. Happy planting!

Sources

Anderson, M. Kat. “Great Blue Lobelia Plant Guide.” plants.sc.egov.usda.gov. https://plants.usda.gov/DocumentLibrary/plantguide/pdf/pg_losi.pdf. Accessed July 10, 2026.
Barton, William P. C., John Boyd, John G. Warnicke, and Tanner, Vallance, Kearny & Co. 1818. Vegetable Materia Medica of the United States; or, Medical Botany: Containing a Botanical, General, and Medical History of Medicinal Plants Indigenous to the United States. Philadelphia: H. C. Carey & I. Lea. https://doi.org/10.5962/bhl.title.119065. Accessed July 13, 2026.
Branhagen, Alan. Native Plants of the Midwest: A Comprehensive Guide to the Best 500 Species for the Garden. Portland, OR: Timber Press, 2016.
Cornell Botanic Gardens. “Blue Lobelia.” cornellbotanicgardens.org. https://cornellbotanicgardens.org/plant/blue-lobelia. Accessed July 13, 2026.
Froberg, Blake, Danyal Ibrahim, and R. Brent Furbee. “Plant Poisoning.” Emergency Medicine Clinics of North America 25, no. 2 (May 2007): 375–433. https://doi.org/10.1016/j.emc.2007.02.013. Accessed July 10, 2026.
Harstad, Carolyn. Go Native! Gardening with Native Plants and Wildflowers in the Lower Midwest (1999), 209–210.
Invasive Plants. Brooklyn, NY: Brooklyn Botanic Garden, 1996.
IUCN Red List. “The IUCN Red List of Threatened Species: Rusty Patched Bumble Bee.” iucnredlist.org, 2014. https://www.iucnredlist.org/species/44937399/46440196. Accessed July 13, 2026.
Lady Bird Johnson Wildflower Center. “Lobelia siphilitica (Great Blue Lobelia).” wildflower.org. Accessed June 20, 2026. https://www.wildflower.org/plants/result.php?id_plant=LOSI.
Morton Arboretum. “Great Blue Lobelia.” mortonarb.org. https://mortonarb.org/plant-and-protect/trees-and-plants/great-blue-lobelia/. Accessed July 12, 2026.
Mt. Cuba Center. “Great Blue Lobelia.” mtcubacenter.org. https://mtcubacenter.org/plants/great-blue-lobelia/. Accessed July 11, 2026.
NatureServe Explorer. “Lobelia siphilitica.” explorer.natureserve.org. https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.135214/Lobelia_siphilitica. Accessed October 6, 2026.
Nelson, Gil. Best Native Plants for Southern Gardens: A Handbook for Gardeners, Homeowners, and Professionals (2010), 213–214.
North Carolina State Extension. “Lobelia siphilitica.” plants.ces.ncsu.edu. Accessed June 20, 2026. https://plants.ces.ncsu.edu/plants/lobelia-siphilitica/.
Schweitzer, Dale F., Nicole A. Capuano, Bruce E. Young, and Sheila R. Colla. “Conservation and Management of North American Bumble Bees.” NatureServe, Arlington, Virginia, and USDA Forest Service, Washington, D.C., 2012. https://www.natureserve.org/publications/conservation-and-management-north-american-bumble-bees. Accessed July 13, 2026.
Smith, Huron Herbert. 1928. Ethnobotany of the Meskwaki Indians. In: Digital General Collection. University of Michigan Library Digital Collections. https://name.umdl.umich.edu/1683322.0001.001. Accessed July 13, 2026.
Sookhan, Nicholas, Thomas M. Onuferko, and J. Scott MacIvor. “Mixed Effects of Urbanization on Pollination Services among Four Native Plant Species.” Ecological Entomology 50, no. 6 (December 2025): 1184–1195. https://doi.org/10.1111/een.70016. Accessed July 10, 2026.
Stewart, Amy. Wicked Plants: The Weed That Killed Lincoln’s Mother & Other Botanical Atrocities. Chapel Hill, NC: Algonquin Books of Chapel Hill, 2009.
USDA PLANTS Database. “Lobelia siphilitica L. Great Blue Lobelia.” plants.usda.gov. https://plants.sc.egov.usda.gov/plant-profile/LOSI. Accessed June 20, 2026.
US Fish and Wildlife Service. “Rusty Patched Bumble Bee.” fws.gov. https://www.fws.gov/species/rusty-patched-bumble-bee-bombus-affinis. Accessed July 13, 2026.

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Emily Lessard & Kat William Hiland

Founder & Editor · Contributor

Emily Lessard is the founder and editor of The Plant Native. Kat William Hiland is a contributor studying horticulture at Temple University; their favorite flower is any species of magnolia.

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