Perennial Flower

When to Plant Black-Eyed Susans in Iowa

Cheerful golden blooms that attract butterflies and tolerate drought. A backbone of the low-maintenance perennial garden.

The Short Answer

In Iowa, plant black-eyed susans based on your regional frost dates. Northern Iowa has a last frost around May 5 - May 20, while Southern Iowa sees frost end around Apr 20 - May 5. Continental climate. Cold winters, warm humid summers. Good growing season with adequate rainfall.

Iowa Frost Dates

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

Region Zones Last Frost (Spring) First Frost (Fall)
Northern Iowa 4b, 5a May 5 - May 20 Sep 20 - Oct 5
Central Iowa 5a, 5b Apr 25 - May 10 Oct 1 - Oct 15
Southern Iowa 5b Apr 20 - May 5 Oct 5 - Oct 20

Black-Eyed Susans Planting Schedule for Iowa

Northern Iowa (Zones 4b, 5a)

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 Iowa (Zones 5a, 5b)

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

Southern Iowa (Zones 5b)

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

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

Growing Black-Eyed Susans in Iowa

Black-Eyed Susans in Iowa's Climate

Black-eyed Susans are native wildflowers that thrive in cold-climate conditions. Plant divisions or nursery plants from spring through early fall. They handle poor soil, drought once established, and cold winters without complaint. Leave seed heads standing through winter for bird food and visual interest.

Soil Considerations for Iowa

Outstanding black prairie soils. Some of the richest agricultural land in the world. Minimal amendment needed.

Iowa Climate & Growing Season

Continental climate. Cold winters, warm humid summers. Good growing season with adequate rainfall. Black-Eyed Susans can handle frost well, which is an advantage in Iowa's climate. You can push planting dates earlier in spring and extend into fall.

Growing season length varies across Iowa: Northern Iowa (4b, 5a) has a last frost around May 5 - May 20, while Southern Iowa (5b) sees frost end around Apr 20 - May 5. This difference matters for black-eyed susans — but black-eyed susans handle frost well, so the timing difference is less critical.

Growing Tips

Leave seed heads standing through winter for birds and visual interest. Self-seeds freely — deadhead if you don't want more.

Companion Planting

Plant black-eyed susans alongside these companions for better growth:

Coneflowers Ornamental Grasses

The Bottom Line

Black-Eyed Susans can be grown successfully across Iowa, but your exact planting dates depend on which region you're in. Northern Iowa gardeners should plan around a May 5 - May 20 last frost, while those in Southern Iowa can typically plant earlier. For exact dates based on your zip code, use our free planting date finder.

Related Guides

Black-Eyed Susans Growing Guide National planting guide with all states Iowa Planting Calendar All plants for Iowa Black-Eyed Susans in Alabama Alabama planting dates Black-Eyed Susans in Alaska Alaska planting dates Black-Eyed Susans in Arizona Arizona planting dates Black-Eyed Susans 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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