Ageratum

Ageratum houstonianum

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verifiedReviewed by the GreenScout Team

Ageratum is a tender annual with soft, fluffy flower clusters in shades of blue, purple, pink, or white that bloom continuously from summer through fall frost. Compact varieties grow 6–12 inches tall, making them ideal for edging and containers, while taller types reach 18–24 inches. This easy-to-grow plant attracts pollinators and thrives in warm, sunny locations with consistent moisture.

Common Problems

Select the problem your Ageratum is experiencing to get a treatment guide.

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Overwateringchevron_right

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Wiltingchevron_right

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Powdery Mildewchevron_right

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Leggy Growthchevron_right

Care Guide

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Light

Full sun to light shade (at least 4–6 hours of direct sun); blooms best in full sun

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Water

Keep soil consistently moist but not waterlogged; water when top inch of soil is dry

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Soil

Well-draining, fertile soil rich in organic matter; pH 5.5–7.5

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Fertiliser

Light monthly feeding with balanced fertilizer; avoid excessive nitrogen which reduces flowering

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Temperature

Warm-loving; 70–85°F ideal; frost-sensitive annual

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Humidity

Moderate to high; prefers 50–70% humidity

Toxicity

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Non-toxic; safe for all pets and children

Common Diseases

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Common Pests

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Seasonal Care

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Resume regular watering and feeding as growth picks up.

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Peak growing season. Water and feed regularly.

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Reduce watering as growth slows. Stop heavy feeding.

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Minimal watering and feeding. Protect from frost if needed.

Frequently Asked Questions

Why won't my Ageratum stop blooming?

It blooms continuously from summer through fall frost — as long as it gets consistent moisture and warm conditions, this tender annual just keeps producing its fluffy flower clusters.

Is Ageratum good for small garden spaces?

Yes — compact varieties grow just 6–12 inches tall, making them ideal for edging and containers, while taller types reaching 18–24 inches work well toward the back of a bed.