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.

You will be able to determine when it's possible to plant violets by looking at the USDA zone info for Grinnell.

Planting Calendar for Violets

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

You can plant violets a little 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 violets 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 violets and expect a good harvest is probably September. You probably don't want to wait any later than that or else your violets may not have a chance to really do well. Starting your violets indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Grinnell. In the coldest months of winter you can expect an average low temperature of -20°F.

Since the USDA zone info for Grinnell may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Grinnell you get surprised by a frost after April 15 so make sure that you are ready to cover your violets if you have a late frost.

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.