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.

The USDA zone info for Ann Arbor can be used to estimate when it's a good idea to plant alternanthera.

Planting Calendar for Alternanthera

Frost tolerance for alternanthera:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's not a good idea to plant alternanthera until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant alternanthera in Ann Arbor 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 alternanthera and expect a good harvest is probably August. If you wait any later than that and your alternanthera may not have a chance to fully mature. If you are starting your alternanthera indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Ann Arbor the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -10°F.

Since the USDA zone info for Ann Arbor may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Ann Arbor last frost occurs after April 15 be ready to protect your alternanthera if you have a surprise late frost.

USDA Zone Info for Ann Arbor

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Ann Arbor

You may be interested in your other planting guides for Ann Arbor.