Annuals & Biennials

Ageratum
flossflower

Height 1/2-2 ft (15-60 cm)
Planting distance for dwarf cultivars
9 in (23 cm); for taller cultivars, 1ft (30 cm)
Flowers early summer to first severe frost
Any moisture-retentive soil
Sheltered, sunny or lightly shaded site
Half-hardy annual

An abundance of flowers and a long season - from early summer until the first severe frost-make Ageratum a popular bedding plant. Its low, compact habit and its powder puff flowers look most effective edging formal beds, filling gaps in borders of low-growing plants or brightening window boxes and containers.
Some of the taller cultivars are useful for flower arranging, combining well with many other garden plants. The original blue- flowered species, Ageratum houstonianum, has largely been replaced by garden cultivars. These come in blue, pink, purple, and white.
The F1 hybrids are first-generation plants obtained by crossing two cultivars known for their ability to produce consistently similar offspring. These hybrids are particularly bigorous and have the largest flower heads. You do, however, pay a little more for the seeds.

Popular species and cultivars
'Adriatic,' an F1 hybrid, has a neat, compact habit, reaching 6-8 in (15-20 cm). It bears midblue flowers.
'Blue Danube' reaches 6-8 in (15-20 cm) high and has lavender-blue blooms. It is one of the best early-flowering F1 hybrids.
'Blue Horizon' is a tall F1 hybrid, growing to 2 ft (60 cm) and good for cutting. Small purple-blue flowers are borne in clusters.
'Blue Mink' is a compact plant reaching 9-12 in (23-30 cm) high. It has powder-blue flowers.
'Blue Ribbon' an F1 hybrid, is smothered in bright midblue flowers from early summer on. It grows 6-8 in (15-20 cm) high.
'Capri' bears rich deep blue flowers on compact plants, 8-12 in (20-30 cm) high.
'Hawaii Hybrids' are compact F1 hybrids growing to a height and spread of 6-8 in (15-20 cm). Available in white, blue and deep lavender, they bloom strongly even in dry soil.
'North Sea,' an F1 hybrid reaching 6-8 in (15-20 cm) high, has deep blue or red flowers that continue until late fall.
'Pacific,' an F1 hybrid, grows 8 in (20 cm) high and forms a tight dome of deep purple flowers on fast-growing plants.
'Pinky Improved Selection' is a new hybrid cultivar of bushy plants. It is 6-8 in (15-20 cm) tall and has dusty pink flowers.
'Southern Cross' grows 8-12 in (20-30 cm) high and can be used for containers, cut flowers, or beds. The flower clusters are bi-colored in pale blue and white.
'Summer Snow' is an F1 hybrid, 6-8 in (15-20 cm) tall, with pure white, fluffy flower heads.
'Swing Mixed' is an F1 hybrid mixture, with flowers in soft shades of blue, purple, rose, and pink. The plants grow to 8 in (20 cm) high.

Annuals
and
Biennials