When to Plant Pearl onions in Marion, IA

One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By referring to the USDA zone info for Marion it's possible to determine when it's the best time 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.

Pearl onions tend to make it in mild cold which tells us that you can plant them just a tiny bit earlier in the year than other frost tender plants.

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 Marion 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 really do well. You can get started a little bit earlier by starting your pearl onions indoors.

Last Frost Date

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

Since the USDA zone info for Marion is just an average the actual date of last frost will vary from year to year. Since half of the time in Marion you get surprised by a frost after April 15 be ready to protect your pearl onions if you have a late frost.

USDA Zone Info for Marion

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 Marion

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