When to Plant Phlox in Mount Prospect, IL

One of the first steps you take when you are making a decision about 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.

By looking at the USDA zone info for Mount Prospect it's a good idea to determine when it's the best time 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 little bit earlier in the year because they are moderately cold tolerant.

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 Mount Prospect 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. You can get started a few weeks earlier by starting your phlox indoors.

Last Frost Date

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

Since the USDA zone info for Mount Prospect is just an average the actual date of last frost is different every year. Half of the time in Mount Prospect it frosts late in the year after April 15 so be sure to be ready to protect your phlox if you have a late frost.

USDA Zone Info for Mount Prospect

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 Mount Prospect

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