Bluemink, far better known in US gardens as ageratum or flossflower, is the fuzzy blue bedding annual seen in summer borders and containers, with tight clusters of powder-puff flower heads. It comes from Mexico and Central America and has escaped from gardens in places, becoming naturalized in parts of the southern US.

Appearance

Appearance
Garden types usually form soft, rounded mounds 6–12 in (15–30 cm) tall; wild plants can reach about 3 ft (1 m). Leaves are softly hairy on both sides.
Leaves
Opposite, toothed, about 1–3 in (3–7 cm) long, with a heart-shaped base.
Flowers
Small fluffy heads with no petal-like rays, packed in dense clusters at stem tips. Blue is most common; pink, purple, and white also occur.
Flowering time
Spring to frost (May–October in North Carolina).
Fruit
Tiny dark seeds about 1/12 in (2 mm) long, each tipped with five pale scales.

Look-alikes

Blue mistflowerConoclinium coelestinum

Blue mistflower is a native perennial that comes back each year, grows 18 in–3 ft (45–90 cm) tall, spreads by underground stems into patches, and blooms from late summer. Garden ageratum is a short annual that dies at the first frost.

Why they get mixed upBoth have fluffy blue-lilac flower heads; mistflower is even nicknamed 'hardy ageratum.'

Tropical whiteweed (billygoat weed)Ageratum conyzoides

Flossflower has sticky, gland-tipped hairs on the little under each flower head and on the flower stalks; billygoat weed has no such glands there. A close-up photo of the flower head base helps.

Why they get mixed upSame genus, with very similar weedy-looking plants and small fuzzy heads.

Where it lives

Typical habitats
  • garden beds
  • containers
  • roadsides
  • waste ground
Range
Native to Mexico and Central America. In the US it is grown as a garden annual and has naturalized in parts of the South.
Preferred conditions
Wild plants turn up in disturbed places such as roadsides, vacant lots, and around homes.
Flowering

Flowers May–Oct

Flowers May–Oct

Life cycle

Seed dispersal
The light seeds travel on wind and water and stick to animals, clothing, and vehicles.

Growing it

Care
A frost-tender annual for full sun to part shade, ideally in rich, moist, well-drained soil. Deer and rabbits seldom bother it.
Toxicity
Contains and is toxic to grazing animals, which can suffer liver damage.

Name and classification

Varieties and forms
Cultivars range from compact edging types to tall cut-flower types, in blue, lavender, pink, white, and raspberry-red.

Conservation

IUCN Red List
NENot EvaluatedNot yet assessed

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Bluemink (Ageratum houstonianum) — identification, habitat & look-alikes | Moeyo