One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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 can be used to estimate when it's a good idea to plant arabis.

Planting Calendar for Arabis

Frost tolerance for arabis:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant arabis a lot earlier in the year because they are very cold tolerant.

The earliest that you can plant arabis 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 arabis and expect a good harvest is probably September. If you wait any later than that and your arabis may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your arabis 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 is different every year. Half of the time in Grinnell it frosts late in the year after April 15 so make sure that you are prepared to protect your arabis if you have a surprise 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.