One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Grinnell should be reffered to in order to estimate when you can plant impatiens.

Planting Calendar for Impatiens

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

Impatiens require warm weather which means that it is important to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant impatiens 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 impatiens and expect a good harvest is probably August. Any later than that and your impatiens may not have a chance to grow to maturity. Starting your impatiens indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Always keep in mind that USDA zone info for Grinnell is just an average and the actual date of last frost is different every year. Since half of the time in Grinnell last frost occurs after April 15 be ready to protect your impatiens in the event of 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.