One of the first steps you take when you are figuring out 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 best time to plant amaranthus in Grinnell should be figured out by using the USDA zone info.

Planting Calendar for Amaranthus

Frost tolerance for amaranthus:	Not tolerant of frost.
When to plant:	After the last frost.

You should not plant amaranthus until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant amaranthus 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 amaranthus and expect a good harvest is probably August. If you wait any later than that and your amaranthus may not have a chance to fully mature. You can get started a few weeks earlier by starting your amaranthus indoors.

Last Frost Date

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

Since the USDA zone info for Grinnell is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Grinnell you get a frost after April 15 so make sure that you are ready to protect your amaranthus 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.