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.

The USDA zone info for Carnegie can be reviewed to estimate when to plant phlox.

Planting Calendar for Phlox

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

You can plant phlox a bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant phlox in Carnegie 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 fully mature. If you are starting your phlox indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Carnegie the average date of last frost happens on April 15. You can expect an average low temperature of -5°F in the coldest months of winter.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Carnegie and it changes from year to year. Half of the time in Carnegie you get a frost after April 15 so always be ready to cover your phlox if you have a surprise late frost.

USDA Zone Info for Carnegie

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 Carnegie

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