One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

You should be able to estimate when to plant pearl onions by reviewing the USDA zone info for Granite City.

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 some cold which means that you can plant them just a tiny bit earlier in the year than other frost tender plants.

The earliest that you can plant pearl onions in Granite City 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. If you are starting your pearl onions indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Granite City the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -5°F.

Since the USDA zone info for Granite City is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Granite City there is a last frost after April 15 so always be ready to cover your pearl onions if you have a surprise late frost.

USDA Zone Info for Granite City

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Granite City

You may be interested in your other planting guides for Granite City.