When to Plant Pearl onions in Harvard, IL

One of the first steps you take when you are figuring out 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 first chance to plant pearl onions in Harvard can be determined by looking at the USDA zone info.


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 one of those plants that can tolerate a tiny bit of cold weather 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 Harvard 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. You probably don't want to wait any later than that or else your pearl onions may not have a chance to grow to maturity. 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 Harvard. You should expect an average low temperature of -15°F in the coldest months of winter.

It's important to remember that USDA zone info for Harvard may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Harvard there is a last frost after April 15 so make sure that you are prepared to protect your pearl onions if you have a late frost.

USDA Zone Info for Harvard

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Harvard

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