Fuzzy blue clusters that fill the filler gap
| Type | Annual |
|---|---|
| Zones | All zones |
| Sun | Full sun to part shade |
| Height | Tall varieties 18–24 inches |
| Bloom Season | Summer to frost |
| Vase Life | 7–10 days |
| Start | Start seeds 6–8 weeks before last frost |
Ageratum (floss flower) produces clusters of fuzzy, powder-puff blooms in lavender-blue, purple, pink, and white. Tall varieties are an underrated cut flower filler, providing the kind of soft, airy blue tone that is rare in the garden. Most people know only the dwarf bedding types—seek out the tall cutting varieties.
'Blue Horizon' is the standard tall cutting ageratum at 24–30 inches with strong stems. 'Red Sea' and 'Timeless Mix' add other color options. Avoid compact bedding types—their stems are too short.
Start seeds indoors 6–8 weeks before last frost. Surface sow—needs light. Transplant after frost into full sun with moderate moisture. Space 12 inches apart. Pinch once for branching. Moderate fertility. Ageratum handles light shade better than most cut flowers.
Cut when most florets in the cluster are open. Harvest in morning and condition in clean water. Strip lower foliage. Good vase life of 7–10 days.
Ageratum is a filler flower that adds cool blue tones to warm-colored arrangements. It pairs beautifully with zinnias, sunflowers, and cosmos. Use in summer bouquets and anywhere you need a soft, textural element. Also useful with dusty miller for a cool-toned palette.