Annual Flower

When to Plant Marigolds in Pennsylvania

The ultimate companion plant. Marigolds repel pests, attract pollinators, and add cheerful color all season long.

The Short Answer

Marigolds are a Pennsylvania garden essential — tough, cheerful, and effective as companion plants for vegetable crops.

Pennsylvania Frost Dates

Your planting dates depend on which part of Pennsylvania you're in. Here are the frost date ranges by region:

Region Zones Last Frost (Spring) First Frost (Fall)
Northern Pennsylvania 5a, 5b, 6a May 5 - May 20 Sep 20 - Oct 5
Central Pennsylvania 5b, 6a, 6b Apr 25 - May 10 Oct 1 - Oct 15
Philadelphia Region 7a, 7b Apr 5 - Apr 20 Oct 15 - Nov 5

Marigolds Planting Schedule for Pennsylvania

Northern Pennsylvania (Zones 5a, 5b, 6a)

Average last frost: May 5 - May 20 · Average first frost: Sep 20 - Oct 5

Start Seeds Indoors
6 wks before frost
Transplant Outside
1 wks after frost
Direct Sow
1 wks after frost

Central Pennsylvania (Zones 5b, 6a, 6b)

Average last frost: Apr 25 - May 10 · Average first frost: Oct 1 - Oct 15

Start Seeds Indoors
6 wks before frost
Transplant Outside
1 wks after frost
Direct Sow
1 wks after frost

Philadelphia Region (Zones 7a, 7b)

Average last frost: Apr 5 - Apr 20 · Average first frost: Oct 15 - Nov 5

Start Seeds Indoors
6 wks before frost
Transplant Outside
1 wks after frost
Direct Sow
1 wks after frost

Growing Marigolds in Pennsylvania

State-Specific Growing Tips

Transplant from mid-May or direct sow after frost. Plant French marigolds throughout vegetable gardens. Deadhead for continuous bloom through frost. Penn State Extension recommends marigolds for pollinator support and pest management.

Recommended Varieties for Pennsylvania

French, African, Signet. All perform well in Pennsylvania.

Common Challenges in Pennsylvania

Slugs on young plants. Japanese beetles occasionally. Otherwise nearly foolproof.

Growing Tips

French marigolds are best for pest control in vegetable gardens. Deadhead spent flowers to keep them blooming until frost.

Companion Planting

Plant marigolds alongside these companions for better growth:

Tomatoes Peppers Squash Beans

The Bottom Line

Marigolds can be grown successfully in Pennsylvania with proper attention to regional frost dates and local growing conditions. Timing varies across the state — Northern Pennsylvania gardeners work with a last frost around May 5 - May 20, while Philadelphia Region sees frost end around Apr 5 - Apr 20. Choose varieties suited to your region, amend your soil based on its specific needs, and monitor for the pests and diseases most common in your area. For exact dates based on your zip code, use our free planting date finder.

Related Guides

Marigolds Growing Guide National planting guide with all states Pennsylvania Planting Calendar All plants for Pennsylvania Marigolds in Alabama Alabama planting dates Marigolds in Alaska Alaska planting dates Marigolds in Arizona Arizona planting dates Marigolds in Arkansas Arkansas planting dates
Note: All dates are based on NOAA 30-year Climate Normals and represent historical averages, not predictions for any specific year. Always check your local weather forecast before planting frost-sensitive crops. Learn about our data sources.

Last reviewed: March 29, 2026

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