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

By looking at the USDA zone info for Joliet it's possible to estimate when it's possible to plant primroses.

Planting Calendar for Primroses

Frost tolerance for primroses:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since primroses are one of those plants that can tolerate quite a bit of cold weather you can plant them quite a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant primroses in Joliet 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 primroses and expect a good harvest is probably September. If you wait any later than that and your primroses may not have a chance to grow to maturity. If you are starting your primroses indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Joliet is not always accurate the actual date of last frost changes from year to year. Half of the time in Joliet last frost occurs after April 15 so be sure to be ready to cover your primroses if you have a late frost.

USDA Zone Info for Joliet

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 Joliet

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