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

A common way of determining when to plant garden mums is to consult the USDA zone info for Grinnell.

Planting Calendar for Garden Mums

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

You can plant garden mums just a bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant garden mums 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 garden mums and expect a good harvest is probably September. Any later than that and your garden mums may not have a chance to really do well. You can get started a few weeks earlier by starting your garden mums indoors.

Last Frost Date

The average date of last frost is April 15 in Grinnell. You can expect an average low temperature of -20°F in the coldest months of winter.

It's important to remember that USDA zone info for Grinnell is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Grinnell last frost occurs after April 15 be ready to protect your garden mums if you have 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.