When to Plant Phlox in Downers Grove, IL

Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant phlox in Downers Grove can be determined by using the USDA zone info.


Planting Calendar for Phlox

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

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

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 Downers Grove 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 fully mature. If you are starting your phlox indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Keep in mind 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 Downers Grove and it changes from year to year. Since half of the time in Downers Grove you get a frost after April 15 be ready to protect your phlox if you have one of those late frosts.

USDA Zone Info for Downers Grove

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 Downers Grove

You may be interested in your other planting guides for Downers Grove.