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When to Plant Marigolds in Delaware

Marigolds (Tagetes patula) are warm-season annuals beloved for their cheerful orange, yellow, and red blooms — and for their well-documented ability to repel pest nematodes in vegetable beds. Easy from seed, drought-tolerant once established, and bloom from early summer until the first hard frost.

Delaware spans USDA hardiness zones 7b (with planting data available), so planting dates vary by your location within the state. Click your zone below for the most accurate dates.

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

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Marigolds Planting Calendar for Delaware

Zone 7b ~235 day growing season · Full guide →

Last frost: March 18 · First frost: November 8 · 235 day season

Activity When Date Range
Start Indoors February 4 Feb 4 – Feb 18
Transplant Outdoors March 18 Mar 18 – Apr 1
Direct Sow March 18 Mar 18 – Apr 8
Bloom May 13 May 13 – Sep 2

Growing Tips for Delaware

Direct-sow after last frost or start indoors 4-6 weeks earlier. Deadhead spent blooms to keep new flowers coming. French marigolds (T. patula) are the most reliable nematode repellents — plant a band around vegetable beds. Tolerate poor soil but bloom best with monthly compost.

Frequently Asked Questions

When should I plant Marigolds in Delaware?

Planting dates for Marigolds in Delaware depend on your USDA zone. Delaware spans zones 7b. Check the planting calendar above for your specific zone's frost dates and planting windows.

What zone is Delaware for planting?

Delaware contains USDA hardiness zones 7b. 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.