How to Grow Ageratum Seeds
Updated on Nov 05, 2021
By Shannon McCabe
Latin name Ageratum houstonianum is an annual flower that is nicknamed "floss flower" for its thread-like appearance. Tufts of true blue color make this a popular landscaping flower. Beware that all parts of this plant are poisonous!
HISTORY
Native to southwestern North America and Central America, ageratum has long been a popular landscaping plant. Short varieties are planted at the front of the border, while tall varieties are excellent for cutting. Attractive to butterflies.
USES
- Ornamental, perfect for beds and borders and containers.
- Butterfly garden.
- An excellent cutting flower.
- Attractive to pollinators like butterflies, wasps, and bees.
- Seeds germinate in 7-10 days.
- Direct sow seeds outdoors in spring, after last frost, or start indoors in trays 6-8 weeks before last frost.
- Surface sow seeds uncovered, as they require light to germinate.
- Ideal germination temperature is 65-75 F.
- Plants are not cold hardy.
- They prefer full sun, but will also grow well in part shade.
- Rich, well-drained soil is best; however, plants are fairly tolerant of a wide range of soil.
- Space plants at least 10 inches apart.
- Do not allow plants to dry out, as they will experience drought stress.
- Deadhead regularly in order to promote more blooms.
PESTS/SPECIAL CONSIDERATIONS
- Mostly pest-free, with some experiencing powdery mildew or whitefly.
- Avoid letting plants dry out; ageratum is not a drought-tolerant plant.
- Harvest the flowers when the heads are spent.
- Spread the flowers on screens to dry, then shake to remove the seeds.
- Seeds remain viable for up to 4 years.
