Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. 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 determine when it's possible to plant pearl onions by looking at the USDA zone info for Evanston.

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 do ok in some cold which tells us that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant pearl onions in Evanston 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 fully mature. You can get started a couple of weeks earlier by starting your pearl onions indoors.

Last Frost Date

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

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Evanston and it is different every year. Since half of the time in Evanston it frosts late in the year after April 15 be ready to cover your pearl onions in the event of a surprise late frost.

USDA Zone Info for Evanston

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 Evanston

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