When to Plant Pearl onions in Clear Lake, IA

The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Clear Lake can be reviewed to estimate when it's possible to plant pearl onions.


Planting Calendar for Pearl onions

Frost tolerance for pearl onions: Tolerant of a very small amount of frost.
When to plant: Up to 3 weeks before last frost.

You can plant pearl onions just a tiny bit earlier in the year because they do ok in moderate cold.

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

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

The last month that you can plant pearl onions and expect a good harvest is probably August. Any later than that and your pearl onions may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your pearl onions indoors.

Last Frost Date

The average date of last frost is April 15 in Clear Lake. In the coldest months of winter you should expect an average low temperature of -20°F.

Since the USDA zone info for Clear Lake is an average the actual date of last frost changes from year to year. Since half of the time in Clear Lake you get a frost after April 15 be ready to cover your pearl onions in the event of one of those late frosts.

USDA Zone Info for Clear Lake

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 Clear Lake

You may be interested in your other planting guides for Clear Lake.