Smith's sunflower (Helianthus smithii)

Smith's sunflower

Helianthus smithii grows in wet, mucky soils in marshes, ditches, and roadsides. It is a perennial herb up to 2.5 m (over 2.5 m) tall, spreading by means of underground rhizomes. One plant usually produces 1-15 flower heads, each containing 12–23 yellow ray florets surrounding 100 or more red, yellow, or brown disc florets.

Scientific classification

Species

Smith's sunflower (Helianthus smithii)

Asters bellflowers fanflowers and allies

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Perennial

Lifespan

Deciduous

Leaf type

20 - 35 ℃

Ideal Temperature

Care Guide for Smith's sunflower

Every week

Water

Full sun

Sunlight

20 - 35 ℃

Ideal Temperature

Water: Smith's sunflower, require moist soil during sowing and transplanting, with increased water during the seedling stage. Peak water demand occurs from bud emergence to blooming. Pot-grown smith's sunflower need timely watering to prevent wilting, while avoiding overly wet conditions to prevent yellowing leaves.

Fertilize: For smith's sunflower in pots, apply liquid fertilizer every 7-10 days, using nitrogen during seedling growth and phosphate-potassium during budding for optimal blooming. In gardens, fertilization depends on soil fertility; apply nitrogen early and phosphate-potassium later if soil is poor, with applications every 20 days.

Pruning: Smith's sunflower, a perennial with vibrant yellow blooms, benefits from pruning in early to late spring. Remove spent flowers and damaged stems to encourage growth. Thinning excess foliage improves air circulation, reducing disease risk, while regular pruning enhances the plant's health and appearance.

Propagation: Smith's sunflower is propagated by sowing seeds and is cross-pollinated, primarily by insects and bees. Artificial pollination during bloom can enhance seed setting and increase seed production.

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