One of the first steps you take when you are determining your gardening schedule is find your 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 will be able to estimate when it's the best time to plant tall phlox by checking out the USDA zone info for Mankato.

Planting Calendar for Tall Phlox

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

Tall Phlox are moderately cold tolerant which tells us that you can plant them a little bit earlier than other frost tender plants.

The earliest that you can plant tall phlox in Mankato is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant tall phlox and expect a good harvest is probably August. You probably don't want to wait any later than that or else your tall phlox may not have a chance to fully mature. If you are starting your tall phlox indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Mankato the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Mankato and it changes from year to year. Half of the time in Mankato you get surprised by a frost after May 15 so make sure that you are ready to cover your tall phlox in the event of a surprise late frost.

USDA Zone Info for Mankato

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Mankato

You may be interested in your other planting guides for Mankato.