blissgarden.

When to plant in Ankeny, IA

USDA Zone 5b

Here are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Ankeny, Iowa — all computed from Ankeny's nearest NOAA weather station.

In zone 5b, Ankeny gardeners can grow many hardy perennials, while the last and first frost still dictate the annual vegetable calendar.

Station · ANKENY · 4.1 km
Last spring frost
April 23
50% chance · 32°F
First fall frost
October 15
50% chance · 32°F
Growing season
175 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for AnkenyA year-band showing 32°F frost risk from January to December for Ankeny: last spring frost around April 23, first fall frost around October 15, about 175 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

Frost probability

ANKENY · 1991–2020

The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Ankeny’s own odds, recorded at ANKENY.

Frost-probability curves for AnkenyProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around April 23 and the first fall frost around October 15, giving about 175 frost-free days.
Last spring frostFirst fall frostbold = 32°F · thin = 28°F / 36°F · dot = 50% date · band = 10–90% window
ThresholdSPRING 10%SPRING 50%SPRING 90%FALL 10%FALL 50%FALL 90%
36°FMay 16May 3Apr 19Sep 21Oct 4Oct 18
32°FMay 6Apr 23Apr 8Sep 30Oct 15Oct 28
28°FApr 27Apr 13Mar 31Oct 11Oct 25Nov 5

Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.

What to plant now

TODAY · JULY 19
Fall sowopen now
Rutabaga
July 9July 23
Fall sowin 4 days
Broccoli
July 23August 6
Fall sowin 4 days
Cabbage
July 23August 6
Fall sowin 4 days
Carrot
July 23August 6
Fall sowin 4 days
Cauliflower
July 23August 6
Fall sowin 4 days
Napa Cabbage
July 23August 20
Fall sowin 18 days
Beet
August 6August 20
Fall sowin 18 days
Collards
August 6September 3
Fall sowin 18 days
Endive
August 6August 20
Fall sowin 18 days
Escarole
August 6August 20
Fall sowin 18 days
Fennel (Bulb)
August 6August 20
Fall sowin 18 days
Kale
August 6September 3
Fall sowin 18 days
Kohlrabi
August 6September 3
Fall sowin 18 days
Peas
August 6August 20
Fall sowin 18 days
Radicchio
August 6August 20
Fall sowin 18 days
Swiss Chard
August 6August 20
Fall sowin 18 days
Turnip
August 6September 3

Add these crops to your calendar (.ics) ↓

Full-year planting calendar

Start indoorsTransplantDirect sowFall sow

Each bar is the exact window to take a planting action in Ankeny, drawn to the day from the local frost dates. The dashed line is today.

Nearby weather stations

3 within 22 km · complete 32°F normals

When stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.

ANKENY
Primary
4 km · 297 m elevation
SPRING
Apr 23
FALL
Oct 15
DES MOINES WSFO-JOHNSTON
10 km · 292 m elevation
SPRING
Apr 19
FALL
Oct 18
DES MOINES INTL AP
22 km · 292 m elevation
SPRING
Apr 18
FALL
Oct 20

Ankeny planting FAQ

When is the last spring frost in Ankeny, IA?

On average, the last spring frost in Ankeny is around April 23 (50% probability at 32°F, from 1991–2020 NOAA normals). Wait until after this date to set out tender plants like tomatoes and peppers.

When is the first fall frost in Ankeny, IA?

The first fall frost in Ankeny typically arrives around October 15 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.

What hardiness zone is Ankeny in?

Ankeny is in USDA hardiness zone 5b. In zone 5b, winters are cold — pick cold-hardy varieties and protect tender crops.

How long is the growing season in Ankeny?

Ankeny has about 175 frost-free days — a moderate growing season — between the average last spring frost (April 23) and first fall frost (October 15).

When should I plant tomatoes in Ankeny?

For Ankeny, sow tomatoes indoors about February 26–March 12 and move the seedlings out around April 30, after the last spring frost.

Planting reminders

Never miss a window in Ankeny

An email when it’s time to start seeds, transplant, and sow — timed to Ankeny’s frost dates. Double opt-in, one-click unsubscribe, no spam.

Nearby cities

8 within reach

Frost dates recorded at ANKENY, 4 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.

Cite this page
BlissGarden. "When to Plant in Ankeny, IA — Frost Dates & Zone 5b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00130241. Retrieved from https://blissgarden.com/iowa/ankeny.