The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of getting a good idea when it's the best time to plant pearl onions is to use the USDA zone info for Marengo.

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 slightly earlier in the year than more sensitive plants.

The earliest that you can plant pearl onions in Marengo 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 grow to maturity. You can get started a few weeks earlier by starting your pearl onions indoors.

Last Frost Date

In Marengo the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Marengo is an average the actual date of last frost is different every year. Since half of the time in Marengo 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 Marengo

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 Marengo

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