Before planting it is a good idea to find your USDA Zone info to estimate 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.

You will be able to figure out when to plant tall phlox by checking out the USDA zone info for Lewistown.

Planting Calendar for Tall Phlox

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

Since tall phlox do well in moderate cold you can plant them a little earlier in the year than more sensitive plants.

The earliest that you can plant tall phlox in Lewistown 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 grow to maturity. You can get started a little bit earlier by starting your tall phlox indoors.

Last Frost Date

The average date of last frost is May 15 in Lewistown. In the coldest months of winter you should expect an average low temperature of -30°F.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Lewistown and it will vary from year to year. Since half of the time in Lewistown last frost occurs after May 15 be ready to cover your tall phlox in the event of a surprise late frost.

USDA Zone Info for Lewistown

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Lewistown

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