Ageratum houstonianum 'Blue Horizon'
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Ageratum houstonianum 'Blue Horizon'

Ageratum houstonianum 'Blue Horizon'

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SKU: S70192
1 for $11.50
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Quick Facts
Common Name: Floss Flower
Hardiness Zone: Annual Exposure: Sun to Part Shade
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Blooms In: Jun-Sep
Mature Height: 24-30" Spacing: 10-12"
Read our Growing Guide Ships as: 1 PINT 28.86 CU IN.
Deer Resistance: Yes
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Product Details

Product Details

Fuzzy flower clusters the color of blueberry ice cream cap the slim stems of Ageratum houstonianum 'Blue Horizon,' adding appealing color and irresistible texture to the garden over a long season. The flower clusters sail through heat, humidity, and rain. This is a super choice for cottage and cut-flower gardens, mixed borders, and containers. Winner of the RHS Award of Garden Merit.

There are perennials and even shrubs in the small genus Ageratum, native to the warm regions of North and South America. But most of us know Ageratum only as an annual for garden beds and containers. The soft, fuzzy-looking flowers range from shades of blue, purple, pink, to white and will attract butterflies all summer. Provide plants with a sunny areas and average soil that does not dry out.

For more information on the growing and care of Ageratum, click Growing Guide.




The size of the plants we ship has been selected to reduce the shock of transplanting. For some, this means a large, bareroot crown. Others cannot travel bareroot or transplant best if grown in containers. We ship these perennials and annuals in 1 pint pots, except as noted. We must point out that many perennials will not bloom the first year after planting, but will the following year, amply rewarding your patience. We ship bulbs as dormant, bare bulbs, sometimes with some wood shavings or moss. Shrubs, Roses, vines, and other woody plants may be shipped bareroot or in pots. The size of the pot is noted in the quick facts for each item.


We ship our bulbs and plants at the right time for planting in your area, except as noted, with orders dispatched on a first-come, first-served basis by climate zone. We also ship a wide range of containers and planters, tools, supplies, fertilizers, garden wear, garden decor items, as well as indoor decorations like wreaths and dried bouquets when available. Estimated dates for shipping are indicated in the green Shipping Details box for each item. Please supply a street address for delivery. Kindly contact us with two weeks notice, if you'll be away at the expected time of delivery.


We guarantee to ship plants that are in prime condition for growing. If your order is damaged or fails to meet your expectations, we will cheerfully replace or refund it. Please contact our Customer Service Department at 1-800-503-9624 or email us at [email protected]. Please include your order number or customer number when contacting us.



Average Customer Rating: 5 out of 5 stars (2 Reviews) Write a Review

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Outstanding annual

Spindly to start, but shortly takes off and makes beautiful addition to garden, compensating for flowerless periods for other annuals and perennials. At 18-24 inches, it makes a great cut flower, giving height to bouquets for indoor use.

23 of 24 people found this review helpful. Do you? yes no  Certified buyer

I order this plant every year!!

A great looking flower in all phases of bloom...even the buds are unique! I can cut for vases all season long and still have plenty of blooms in my flower bed. No downside to this plant at all.

24 of 24 people found this review helpful. Do you? yes no

Growing guide

Growing guide
Print Grow Guide

Latin Name Pronunciation: aj-er-ay'tum    

Floss flower will bloom continuously from June until fall. They have soft, fuzzy-looking flowers in clusters on compact, mounding plants. Their sturdy stems stay erect even through wind and rain.

Grow Ageratum in full sun and average soil with even moisture, 10-12″ apart.  Use good potting soil if planted in pots, fertilizing every 2 weeks with a well-balanced fertilizer. Occasional deadheading will improve performance. Floss flower is beautiful in both garden beds and containers, and makes a good cut flower.

For information on planting and care of annuals, click here.