Last frost date in Ames, Iowa
April 26
Average last frost in spring. In an early year (1 in 10) it's over by April 11; in a late year (1 in 10) it comes after May 9.
October 8
Average first frost in fall. 1 year in 10 it comes by September 23.
Source: NOAA U.S. Climate Normals 1991–2020, station Ames Muni AP (USW00094989), 2.4 miles from Ames, elevation 930 ft. NOAA National Centers for Environmental Information. These are long-term averages, not a forecast.
| Early year | Average | Late year | |
|---|---|---|---|
| Last frost in spring | Apr 11 | Apr 26 | May 9 |
| First frost in fall | Sept 23 | Oct 8 | Oct 21 |
An early or late year is one in 10: 1 year in 10 the frost comes before the early date, and 1 year in 10 after the late date.
Frost-free days in an average year: 164
Planting calendar for Ames
Fall planting
USDA dates for places whose average first freeze is about October 10 (Ames: October 8).
- Eggplant plantsMay 15 – June 15 (past for this year)
- PotatoesMay 15 – June 15 (past for this year)
- Sweet potatoesMay 20 – June 10 (past for this year)
- Black-eyed peasJune 1 – July 1 (past for this year)
- Cabbage plantsJune 1 – July 15 (past for this year)
- Cantaloupe (muskmelon)June 1 – 15 (past for this year)
- CarrotsJune 1 – July 20 (past for this year)
- Cauliflower plantsJune 1 – July 25 (past for this year)
- Celery and celeriac plantsJune 1 – July 15 (past for this year)
- CucumbersJune 1 – July 1 (past for this year)
- Lima beansJune 1 – 15 (past for this year)
- New Zealand spinachJune 1 – July 15 (past for this year)
- OkraJune 1 – July 15 (past for this year)
- ParsnipsJune 1 – July 10 (past for this year)
- Peppers plantsJune 1 – July 1 (past for this year)
- SalsifyJune 1 – July 1 (past for this year)
- SoybeansJune 1 – 25 (past for this year)
- Summer squashJune 1 – July 15 (past for this year)
- Sweet cornJune 1 – July 10 (past for this year)
- Swiss chardJune 1 – July 20 (past for this year)
- TomatoesJune 1 – 20 (past for this year)
- WatermelonJune 1 – 15 (past for this year)
- Winter squashJune 1 – July 1 (past for this year)
- Witloof chicoryJune 1 – July 1 (past for this year)
- BeetsJune 15 – July 25 (past for this year)
- Broccoli plantsJune 15 – July 15 (past for this year)
- Brussels sprouts plantsJune 15 – July 15 (past for this year)
- Chinese cabbageJune 15 – Aug 1 (past for this year)
- Florence fennelJune 15 – July 15 (past for this year)
- ParsleyJune 15 – Aug 1 (past for this year)
- RutabagaJune 15 – July 15 (past for this year)
- Snap beansJune 15 – July 20 (past for this year)
- Collards plantsJuly 1 – Aug 1 (past for this year)
- EndiveJuly 1 – Aug 15 (past for this year)
- KaleJuly 1 – Aug 1 (past for this year)
- KohlrabiJuly 1 – Aug 1 (past for this year)
- SorrelJuly 1 – Aug 1 (past for this year)
- TurnipsJuly 1 – Aug 1 (past for this year)
- DandelionJuly 15 – Sept 1 (past for this year)
- Head lettuce plantsJuly 15 – Aug 15 (past for this year)
- Leaf lettuceJuly 15 – Sept 1 (past for this year)
- Mustard greensJuly 15 – Aug 15 (past for this year)
- RadishesJuly 15 – Sept 15 (past for this year)
- SpinachAug 1 – Sept 1 (past for this year)
- Corn saladAug 15 – Sept 15 (past for this year)
- Upland cressAug 15 – Sept 15 (past for this year)
- Rhubarb plantsOct 15 – Nov 15Now
- Asparagus plantsOct 20 – Nov 15Now
USDA lists chervil and chives, garlic, horseradish, leeks, onion plants, onion seed, onion sets, garden peas, shallots as generally spring-planted here.
Spring planting
USDA dates for places whose average last freeze is about April 30 (Ames: April 26).
- Corn saladMar 1 – May 1
- Onion setsMar 10 – Apr 10
- Cabbage plantsMar 15 – Apr 10
- GarlicMar 15 – Apr 15
- Onion seedMar 15 – Apr 15
- Asparagus plantsMar 20 – Apr 15
- Chervil and chivesMar 20 – Apr 20
- DandelionMar 20 – Apr 20
- Garden peasMar 20 – May 1
- PotatoesMar 20 – May 10
- RadishesMar 20 – May 10
- Rhubarb plantsMar 20 – Apr 15
- SpinachMar 20 – Apr 20
- TurnipsMar 20 – May 1
- BeetsApr 1 – June 15
- Broccoli plantsApr 1 – May 1
- Brussels sprouts plantsApr 1 – May 1
- Collards plantsApr 1 – June 1
- EndiveApr 1 – May 1
- Florence fennelApr 1 – May 1
- Head lettuce plantsApr 1 – May 1
- Horseradish plantsApr 1 – 30
- KaleApr 1 – 20
- KohlrabiApr 1 – May 10
- Leaf lettuceApr 1 – June 1
- LeeksApr 1 – May 1
- Mustard greensApr 1 – May 10
- Onion plants plantsApr 1 – May 1
- ParsleyApr 1 – May 1
- ParsnipsApr 1 – May 1
- SalsifyApr 1 – May 15
- ShallotsApr 1 – May 1
- SorrelApr 1 – May 15
- CarrotsApr 10 – June 1
- Cauliflower plantsApr 10 – May 10
- Upland cressApr 10 – May 10
- Celery and celeriac plantsApr 15 – May 1
- Swiss chardApr 15 – June 15
- New Zealand spinachMay 1 – June 15
- RutabagaMay 1 – June 1
- Summer squashMay 1 – 30
- OkraMay 10 – June 1
- Snap beansMay 10 – June 30
- Sweet cornMay 10 – June 15
- TomatoesMay 10 – June 15
- Black-eyed peasMay 15 – June 1
- Cantaloupe (muskmelon)May 15 – June 15
- CucumbersMay 15 – June 15
- Eggplant plantsMay 15 – June 10
- Lima beansMay 15 – June 15
- Peppers plantsMay 15 – June 10
- SoybeansMay 15 – June 15
- WatermelonMay 15 – June 15
- Sweet potatoesMay 20 – June 10
- Witloof chicoryJune 15 – July 1
USDA lists chinese cabbage as generally fall-planted here.
Planting dates: USDA Home and Garden Bulletin No. 9 (1967), “Suburban and Farm Vegetable Gardens,” tables 4 and 5 (earliest safe spring and latest safe fall dates), applied to this place's NOAA frost dates. “Plants” means setting out transplants, not sowing seed. How we match the table.