Planting calendar

When to plant cucumbers in Iowa

Iowa spans USDA hardiness zones 4b-5b. Average last spring frost: 05-05. This calendar gives you the indoor start, transplant, and direct-sow dates for Cucumis sativus.

Iowa planting dates for cucumbers

PhaseDate in IowaNotes
Start seeds indoorsApril 143 weeks before last frost
Transplant outdoorsMay 192 weeks after last frost
Direct sow outsideMay 121 weeks after last frost

Why these dates

Cucumbers germinate quickly in warm soil (70F+) but get destroyed by cucumber beetles - row covers until flowering are essential in much of the US.

The dates above are anchored to Iowa's average last spring frost date of 05-05, with offsets standard across university Extension publications. For zone-specific local timing, use the frost date lookup tool with your ZIP code.

More on growing cucumbers

The full growing guide for cucumbers - varieties, soil, fertilization, pests, harvest, storage - is here: Cucumbers growing guide.

More Iowa planting information

Sources