Perennial Flower

When to Plant Daylilies in Pennsylvania

Nearly indestructible perennials with stunning trumpet-shaped blooms. Each flower lasts just one day, but the show goes on for weeks.

The Short Answer

Daylilies are one of Pennsylvania's most reliable perennials — tough, beautiful, and productive in the state's four-season climate.

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

Daylilies Planting Schedule for Pennsylvania

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

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

Transplant Outside
0 wks after frost

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

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

Transplant Outside
0 wks after frost

Philadelphia Region (Zones 7a, 7b)

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

Transplant Outside
0 wks after frost

Growing Daylilies in Pennsylvania

State-Specific Growing Tips

Plant from late April through September. Full sun for maximum bloom. Daylilies tolerate Pennsylvania's varied soils, including heavy clay. Divide every 3-4 years to maintain vigor. Dormant varieties are the safest for northern PA's cold winters.

Recommended Varieties for Pennsylvania

Stella de Oro, Happy Returns. Dormant types for Zone 5b areas. Penn State Extension recommends daylilies as low-maintenance perennials.

Common Challenges in Pennsylvania

Daylily rust. Deer browse in rural areas. Nearly indestructible otherwise.

Growing Tips

Plant bare-root or divisions in spring or fall. Divide clumps every 3-4 years to maintain vigor. Deadhead to keep gardens tidy.

Companion Planting

Plant daylilies alongside these companions for better growth:

Coneflowers Black Eyed Susans

The Bottom Line

Daylilies 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

Daylilies Growing Guide National planting guide with all states Pennsylvania Planting Calendar All plants for Pennsylvania Daylilies in Alabama Alabama planting dates Daylilies in Alaska Alaska planting dates Daylilies in Arizona Arizona planting dates Daylilies 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

Ready to Start Planting?

Enter your zip code and pick your plant. We'll tell you exactly when to plant, start seeds, and harvest — based on where you live.

Find Your Planting Dates