Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to figure out when it's a good idea to plant phlox by looking at the USDA zone info for River Rouge.

Planting Calendar for Phlox

Frost tolerance for phlox:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Phlox do ok in some cold which tells us that you can plant them a little bit earlier in the year than other frost tender plants.

The earliest that you can plant phlox 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 phlox and expect a good harvest is probably September. Any later than that and your phlox may not have a chance to really do well. If you are starting your phlox indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for River Rouge is an average the actual date of last frost will vary from year to year. Half of the time in River Rouge you get a frost after April 15 so be sure to be ready to protect your phlox if you have 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.