Kona Blue, Ageratum

Kona Blue Ageratum Seed

Mid-blue floss flowers form tidy mounded plants
Handles hot humid summers with dependable garden performance
Compact dimensions suit pots, edging, and border fronts
Performs well in either full or partial sun

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Key Attributes

Botanical Name

Ageratum houstonianum

Days to maturity

85 Days

Sun

Full Sun

Packet

50 Seeds

About Kona Blue, Ageratum Seed, Ageratum Seed

Kona Blue ageratum produces vibrant, deep blue, pom-pom-like flowers on compact plants reaching about 5–8 inches tall. Its low, tidy habit is well suited to borders, containers, and ground cover. The blooms attract butterflies and other pollinators and continue from summer into fall. Grow in full sun to partial shade in well-drained soil for a long-lasting display of rich color.

Growing details

Planting

Sow Depth

Top of Soil

Days to Germination

7–14 days

Germination Type

D - Surface Sow

In-row plant spacing

6-12"

Plant profile

Life Cycle

Annual

Plant Height

12 inches

Growth Habits

Compact, Mounding

Seed & variety

Seeds Per Ounce

168,000

Color

Blue

Seed Type

Open Pollinated

Before Planting

Work finished compost into a sunny bed, but keep fertility moderate so ageratum stays compact. Level the surface for its dustlike seed and choose an airy site; seedlings are prone to damping-off in stagnant, wet conditions.

Planting

Start ageratum indoors 6–8 weeks before the last spring frost. Press the fine seed onto the surface, maintain 70–75°F, and keep it consistently moist until germination. Provide strong light after emergence and thin to one sturdy seedling per cell. Harden plants gradually and transplant after frost danger has passed and both soil and nights are warm.

Watering

Ageratum performs best with steady moisture rather than cycles of wilting and saturation. Check the upper inch of soil, irrigate at the base when it begins to dry, and water containers sooner during hot weather.

Fertilizer

Compost usually carries garden plants through the season. If leaves pale or container growth slows, apply a half-strength balanced feed; discontinue high-nitrogen products that produce soft foliage and fewer flower clusters.

Harvesting

Cut ageratum stems when roughly one-third to one-half of the flower clusters are open and strongly colored. Harvest early in the day, strip foliage that would sit below water, and place stems into clean water immediately. Regular cutting or deadheading keeps new clusters forming.

Tips

Pinch the growing tip after several leaf pairs form to build a fuller plant. Shear back tired blooms by about one-third in midsummer, then water well to stimulate a fresh flush.

Pests & Diseases

Watch for powdery mildew, Botrytis blight, and damping-off or root rot. White coating, gray fuzzy growth, collapsing seedlings, or darkened stems signal trouble. Start with clean mix, space plants for airflow, water at soil level, and remove diseased tissue promptly. Avoid working among wet plants.

Inspect ageratum growing tips for aphids and whiteflies, flowers for thrips, and lower leaves for spider-mite stippling. Slugs may damage young plants near the soil. Begin with water sprays, hand removal, or traps; treat before buds open when possible to protect pollinators.