The USDA Zone info is a great tool for gardeners to help us estimate 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.

It's possible to estimate when you can plant spinach by reviewing the USDA zone info for Zone 4b.

Planting Calendar for Spinach

Frost tolerance for spinach:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Spinach are one of those plants that can tolerate a little bit of cold weather which means that you can start planting them earlier than other frost tender plants.

The earliest that you can plant spinach in Zone 4b 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 spinach and expect a good harvest is probably August. You probably don't want to wait any later than that or else your spinach may not have a chance to grow to maturity. Starting your spinach indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Zone 4b. In the coldest months of winter you can expect an average low temperature of -25°F.

Since the USDA zone info for Zone 4b is just an average the actual date of last frost is different every year. Half of the time in Zone 4b last frost occurs after May 15 so just be sure to be ready to cover your spinach in the event of a surprise late frost.

USDA Zone Info for Zone 4b

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Zone 4b

You may be interested in your other planting guides for Zone 4b.