One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can estimate when to plant liatris in River Rouge by using the USDA zone info.

Planting Calendar for Liatris

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

Liatris can survive in pretty solid cold which means that you can plant them earlier in the year than other frost tender plants.

The earliest that you can plant liatris in River Rouge 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 liatris and expect a good harvest is probably September. If you wait any later than that and your liatris may not have a chance to really do well. Starting your liatris indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In River Rouge the average date of last frost happens on April 15. It might get as low as -5°F during the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for River Rouge and it changes from year to year. Half of the time in River Rouge last frost occurs after April 15 so just be sure to be ready to cover your liatris in the event of a late frost.

USDA Zone Info for River Rouge

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in River Rouge

You may be interested in your other planting guides for River Rouge.