When to Plant Onions in Anamosa, IA

Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when you can plant onions in Anamosa by looking at the USDA zone info.


Planting Calendar for Onions

Frost tolerance for onions: Very tolerant of frost.
When to plant: Up to 7 weeks before last frost.

Onions do ok in a bit of cold which tells us that you can plant them much earlier in the year than other plants that might not handle the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant onions
Possibly ok, but a risky time to plant onions
Probably not a good time to plant onions

The earliest that you can plant onions in Anamosa is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant onions and expect a good harvest is probably September. If you wait any later than that and your onions may not have a chance to fully mature. If you are starting your onions indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Anamosa. You should expect an average low temperature of -20°F in the coldest months of winter.

Always keep in mind that USDA zone info for Anamosa is an average and the actual date of last frost changes from year to year. Half of the time in Anamosa there is a last frost after April 15 so always be ready to protect your onions in the event of a late frost.

USDA Zone Info for Anamosa

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-20°F
Highest Expected Low-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Anamosa

You may be interested in your other planting guides for Anamosa.