Monarch Magic Flossflower (Ageratum houstonianum 'Agerboyuma') offers a delightful mound of soft, periwinkle-blue blooms that reliably flower from late spring into summer. Its fuzzy clusters stand above rich green foliage that adds an attractive accent to gardens or containers. Reaching about 6-12 inches tall and spreading 8-16 inches wide, this annual delivers a neat, low-growing shape perfect for brightening borders or pots on sunny patios. Hummingbirds and butterflies gravitate to the flower heads, making this plant an excellent choice for those seeking a pollinator-friendly display.
Monarch Magic Flossflower grows best in full sun to part sun and has moderate moisture needs. Originally from tropical areas, it adapts well in warmer hardiness zones and continues blooming through summer’s heat. Its growth habit is both spreading and neatly mounded, making it ideal for large container plantings, mixed borders, or mass plantings of colorful groundcover. While pollinators love its nectar, deer and rabbits usually avoid it, so you get uninterrupted splashes of blue throughout the season.
Monarch Magic Flossflower Care
Place Monarch Magic Flossflower where it will receive at least four hours of sunlight, but six or more hours are ideal for top performance. Water thoroughly during planting to settle roots, then keep soil moderately moist, letting the surface dry slightly between waterings. A light, balanced fertilizer every few weeks supports steady growth and flowering, though overly rich soil can cause leggy growth. A soil pH near neutral is typically fine, and regular inspection for aphids or mildew helps keep the plant healthy. If growing in containers, use a high-quality, well-drained potting mix.
Light deadheading is optional but can promote fresh blooms if the flowers begin to fade. Pinching or snipping away any leggy stems will encourage a fuller, denser habit. If grown in a container, consider trimming back spent or weakened stems to improve air circulation. Since this plant is treated as an annual in most regions, you can discard it after frost or bring it indoors for a short ornamental display before it finishes its life cycle.
Monarch Magic Flossflower Spacing
When creating a colorful border, space plants about 8 to 12 inches apart so they can fill in without overcrowding. If you plan to feature one plant in a container, a pot about 8 to 10 inches in diameter is sufficient. If combining multiple plants in the same container, pick a slightly larger pot—around 12 inches—to accommodate root growth and provide airflow.
- SKU:
- MMFMONARC-GC
Container Sizes
Please Note: The pictures below are to give a general representation of the different container sizes. The actual size/ages of plants are estimates and will vary based on type of plant, time of year, last pruning & many other factors.

3.5" Pot
Also Known As:
3.5" Container
Plant Age:
~ 6 months
Plant Size:
~ 3"-6"
Pot Size:
~ 4.5"H x 3.75"W
Volume:
~1.42 quarts

4.25" Pot
Also Known As:
4.25" Container
Plant Age:
~ 6 months
Plant Size:
~ 3"-6"
Pot Size:
~ 4.93"H x 4.25"W
Volume:
~1.56 pints

Quart Pot
Also Known As:
Quart
Plant Age:
~ 6 months - 1 year
Plant Size:
~ 4"-8"
Pot Size:
~ 4.75"H x 4.5"W
Volume:
~1.50 quarts

#1 Pot
Also Known As:
#1 Container
1 Gallon
Plant Age:
~ 1 - 2 years old
Plant Size:
~ 10"-14"
Pot Size:
~ 7"H x 7.75"W
Volume:
~2.26-3.73 quarts

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Arrival Guarantee
We want your plants to arrive in great condition! If you notice any issues upon delivery, contact us within 3 days.
30 Days
For annuals, houseplants & vegetables, we provide a 30-day warranty to ensure that your plants thrive.

Pre-Ordered Plants
Pre-ordered plants are scheduled to ship in Spring 2025. We carefully plan our shipping dates based on your USDA Plant Hardiness Zone to ensure optimal planting conditions upon arrival. Want it sooner/later? Reach out, and we'll try our best to accommodate.
Estimated Spring Shipping Schedule
Estimated ship week for pre-ordered plants will ship based on growing zones as shown below.
Growing Zone | Estimated Ship Week |
---|---|
Zone 10 | March 24th |
Zone 9 | March 31st |
Zone 8 | April 7th |
Zone 7 | April 14th |
Zone 6b | April 21st |
Zone 6a | April 28th |
Zone 5b | May 5th |
Zone 5a | May 12th |
Zone 4 | May 19th |
Zone 3 | May 26th |
Note: These are only estimated ship dates. Plants may ship out later depending on weather & growing conditions of the plant.
Note: Only plants indicated as pre-order will ship as shown above. All other plants and hard goods will ship as normal.
Plants Shipping Now
Plants that are currently in stock typically ship within 2-7 business days after your order is placed.