Blog

When to Plant Petunia in Hawaii

Petunias (Petunia x hybrida) are warm-season tender annuals prized for their prolific, trumpet-shaped blooms in nearly every color. They perform from hanging baskets to garden borders and bloom continuously from late spring until frost, provided spent flowers are removed regularly.

Hawaii spans USDA hardiness zones 11a (with planting data available), so planting dates vary by your location within the state. Click your zone below for the most accurate dates.

Find Your County

Click your county for exact Petunia planting dates based on your local frost dates.

Hover over a county to see details. Click to view planting guide.

Petunia Planting Calendar for Hawaii

Zone 11a ~364 day growing season · Full guide →

Last frost: January 1 · First frost: December 31 · 364 day season

Activity When Date Range
Start Indoors November 6 Nov 6 – Nov 20
Transplant Outdoors November 6 Nov 6 – Nov 20
Bloom January 15 Jan 15 – Aug 13

Growing Tips for Hawaii

Start seeds indoors 8–10 weeks before last frost; seeds need light to germinate — press onto moist mix surface, do not cover. Transplant after last frost once nights stay above 50°F. Pinch back leggy plants mid-summer to encourage bushy re-bloom. Wave/spreading types tolerate light shade but bloom less. Feed every 2 weeks with balanced fertilizer once established.

Frequently Asked Questions

When should I plant Petunia in Hawaii?

Planting dates for Petunia in Hawaii depend on your USDA zone. Hawaii spans zones 11a. Check the planting calendar above for your specific zone's frost dates and planting windows.

What zone is Hawaii for planting?

Hawaii contains USDA hardiness zones 11a. Your specific zone depends on your location within the state — northern and higher-elevation areas are in colder zones, while southern and coastal areas are warmer.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Last updated: July 2026.