Whirlybird Mahogany

Nasturtium

Zone 4b Save Garden

Botanical illustration of Whirlybird Mahogany

🌱 50d to harvest Bush

Velvety mahogany blooms swirl with a beguiling, warm intensity, as if the garden has been brushed with espresso-dark pigment. Whi…

Crop Dates

Milestone	Date
Start Indoors	Direct Sow
Last Frost	May 13th
Transplant / Sow Outdoors	May 13th
Harvest Begins	Jul 2nd
Harvest Ends	Sep 27th

Crop Details

Trait	Value
Days to Maturity	50
Sun Requirements	Full Sun
Growth Habit	Bush
Support Needed	None
Planting Depth	Normal
Germination Temp (°F)	70
Min Soil Temp (°F)	40
Min Night Temp (°F)	35
Harden Off (days)	Not Required

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Frequently Asked Questions

What pest or disease commonly affects Tropaeolum majus (Whirlybird Mahogany), and how can I treat it?

Nasturtiums like Tropaeolum majus are commonly bothered by aphids and can also get powdery mildew in humid, crowded conditions. Spray aphids off with a strong jet of water or use insecticidal soap, and improve airflow by spacing plants and removing any heavily mildewed leaves. If powdery mildew appears, repeat a labeled mildew spray as needed and avoid overhead watering to keep foliage dry.

How often should I water Tropaeolum majus during its main growing phase?

During active growth, water deeply only when the top 1 inch of soil feels dry, since Tropaeolum majus prefers evenly moist but not soggy soil. In full sun, this is often about 2–3 times per week, but reduce frequency after flowering begins if the soil stays moist. Keep the soil from staying waterlogged—wet roots can trigger leaf yellowing and fungal issues.

How can I tell when Whirlybird Mahogany (Tropaeolum majus) is ready to harvest?

Harvest for blooms about 45–55 days after sowing, when plants are actively flowering (fresh flowers form continuously as long as you keep harvesting). For seed harvest, wait until the seed pods swell and turn from green to pale tan, then collect them before they fully dry and scatter. Snip flowers in the morning for best quality and keep removing blooms to encourage more production.

Velvety mahogany blooms swirl with a beguiling, warm intensity, as if the garden has been brushed with espresso-dark pigment. Whirlybird Mahogany nasturtium forms a trailing cascade of rounded leaves and richly colored flowers with a peppery, tangy bite and a tender, juicy texture that shines in fresh arrangements and vibrant garnishes. Grow it for its showy, ornamental splash—an easy, fast performer that matures in about 50 days and rewards with continuous color.

Sowing Tips

Transplant Conditions

Wait until soil reaches 40°F and nights stay above 35°F before moving outdoors.

Expert Note

For the most vibrant mahogany blooms and compact form, plant in full sun and avoid excess nitrogen (too much feed encourages leaf growth over flowers).