General Plant Information (Edit)
Plant Habit: Herb/Forb
Life cycle: Perennial
Sun Requirements: Full Sun to Partial Shade
Water Preferences: Wet Mesic
Minimum cold hardiness: Zone 4a -34.4 °C (-30 °F) to -31.7 °C (-25 °F)
Maximum recommended zone: Zone 9b
Plant Height: 12 - 36 inches
Plant Spread: 6 - 12 inches
Flowers: Showy
Flower Color: Blue
Bloom Size: Under 1"
Flower Time: Summer
Late summer or early fall
Underground structures: Rhizome
Uses: Groundcover
Will Naturalize
Wildlife Attractant: Bees
Resistances: Deer Resistant
Rabbit Resistant
Propagation: Seeds: Stratify seeds: Two months cold moist treatment
Depth to plant seed: Seed is small. Sow on soil surface.
Suitable for wintersowing
Can handle transplanting
Other info: This plant self seeds.
Propagation: Other methods: Cuttings: Tip
Pollinators: Beetles
Moths and Butterflies

Common names
  • Blue Mistflower
  • Wild Ageratum
  • Hardy Ageratum
Botanical names
  • Accepted: Conoclinium coelestinum
  • Synonym: Eupatorium coelestinum

This plant is tagged in:

  • Posted by ILPARW (southeast Pennsylvania - Zone 6b) on Feb 16, 2018 9:43 PM concerning plant:
    I occasionally see this lower perennial in gardens. It is a native plant growing in upland sites as in woodland edges or in low moist sites from Missouri to New Jersey down deep into the South. This plant spreads a lot by rhizomes to become a colony or groundcover and can be aggressive in gardens invading around other plants. It is slow to come up in the spring. Some are sold by most conventional nurseries and some by many native plant nurseries.
  • Posted by Catmint20906 (PNW WA half hour south of Olympia - Zone 8a) on Aug 2, 2014 7:55 PM concerning plant:
    Conoclinium coelestinum is a nectar source for monarchs and other butterflies, and is a plant option for Monarch Way Stations.

    According to NPIN, this plant also has special value to native bees, and supports conservation biological control by attracting beneficial insects to the garden.
  • Posted by jmorth (central Illinois) on Sep 7, 2015 1:46 PM concerning plant:
    A showy wildflower in Illinois, blooming late summer into the fall. Flower heads found at the tops of branching stems are flat-topped clusters of blue, or maybe purple. Each flower head has between 35 and 70 individual disk flowers. Leaves are opposite and toothed at edges. Plant can spread by underground runners. Its favored habitat is moist ground by streams; also found by ditches and low pasture areas. Common in the bottom 2/3 of the state.
    When viewed from a distance, may look like a low-lying foggy mist.
    I've found it in the fall near woods, in woods, and next to creeks along the Mississippi River.
Plant Events from our members
piksihk On November 1, 2014 Bloomed
Catmint20906 On June 13, 2015 Obtained plant
MrsBinWY On September 22, 2018 Transplanted
On 9-22-2018, planted 7 by 'St. Theresa' grape & 3 by 'Goldflame' honeysuckle in front side yard.
MrsBinWY On June 24, 2018 Potted up
10 pots
MrsBinWY On February 24, 2018 Seeds sown
WS in milk jug; lots of seeds from docmom
MrsBinWY On January 2, 2016 Seeds sown
WS 16 seeds from docmom; seeds germinated well; seedlings were potted up; I failed to water them after I planted them out. Try again.
aspenhill On May 4, 2020 Obtained plant
Black Creek Greenhouse - qty 2
aspenhill On August 27, 2019 Obtained plant
Meadows Farms - qty 5
dnrevel On November 8, 2021 Bloomed
Bloomed and blooming into November. Vigorous plant. May need pinching back for fuller plant and less need for staking.
dnrevel On April 5, 2021 Seeds germinated
Sprouted in WS container.
dnrevel On January 4, 2021 Seeds sown
Winter Sowed to stratify seeds: Two months cold moist treatment
Depth to plant seed: Seed is small. Sow on soil surface.
Suitable for winter sowing
WebTucker On October 25, 2021 Bloomed
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