When to Plant Phlox in Prospect Heights, IL

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.

The USDA zone info for Prospect Heights should be used to estimate when it's a good idea 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.

Phlox are moderately cold tolerant which means that you can start planting them earlier than other frost tender plants.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant phlox
Possibly ok, but a risky time to plant phlox
Probably not a good time to plant phlox

The earliest that you can plant phlox in Prospect Heights 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. You probably don't want to wait any later than that or else your phlox may not have a chance to grow to maturity. Starting your phlox indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Just be sure to remember that USDA zone info for Prospect Heights is just an average and the actual date of last frost is different every year. Half of the time in Prospect Heights you get a frost after April 15 so just be sure to be ready to cover your phlox in the event of a surprise late frost.

USDA Zone Info for Prospect Heights

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-15°F
Highest Expected Low-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Prospect Heights

You may be interested in your other planting guides for Prospect Heights.