When to Plant Pearl onions in Posen, IL

One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Posen can be looked at to determine when it's a good idea 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.

Since pearl onions are barely cold tolerant you can plant them a 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 Posen 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. If you wait any later than that and your pearl onions may not have a chance to grow to maturity. Starting your pearl onions indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Posen. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Posen is just an average the actual date of last frost will vary from year to year. Since half of the time in Posen there is a last frost after April 15 be ready to cover your pearl onions in the event of a late frost.

USDA Zone Info for Posen

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-10°F
Highest Expected Low-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Posen

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