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.

One way of determining when to plant primroses is to refer to the USDA zone info for Mokena.

Planting Calendar for Primroses

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

Primroses are very cold tolerant which tells us that you can plant them much earlier than more sensitive plants.

The earliest that you can plant primroses in Mokena 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. Any later than that and your primroses may not have a chance to fully mature. If you are starting your primroses indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Mokena. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Mokena may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Mokena you get a frost after April 15 so always be ready to protect your primroses in the event of a surprise late frost.

USDA Zone Info for Mokena

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 Mokena

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