One of the best tools that you have as gardeners to help us determine 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.

It's possible to figure out when it's the best time to plant spinach by checking out the USDA zone info for Grinnell.

Planting Calendar for Spinach

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

Spinach are moderately cold tolerant which means that you can start planting them earlier than plants that are more sensitive to the cold.

The earliest that you can plant spinach in Grinnell is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant spinach and expect a good harvest is probably September. If you wait any later than that and your spinach may not have a chance to really do well. If you are starting your spinach indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Grinnell the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -20°F.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Grinnell and it can change quite a bit from year to year. Since half of the time in Grinnell there is a last frost after April 15 be ready to cover your spinach in the event of one of those late frosts.

USDA Zone Info for Grinnell

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Grinnell

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