Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Grinnell you can determine when it's possible to plant cuphea by referring to the USDA zone info.

Planting Calendar for Cuphea

Frost tolerance for cuphea:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Cuphea require warm weather which means that you must wait until it warms up after the last frost has passed before you can plant them.

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

The last month that you can plant cuphea and expect a good harvest is probably August. If you wait any later than that and your cuphea may not have a chance to really do well. You can get started a couple of weeks earlier by starting your cuphea indoors.

Last Frost Date

In Grinnell the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Grinnell is not always accurate the actual date of last frost changes from year to year. Since half of the time in Grinnell it frosts late in the year after April 15 be ready to protect your cuphea 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.