One of the first steps you take when you are getting a good idea 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 reviewing the USDA zone info for Wilmette you should be able to determine when it's a good idea 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.

Primroses do ok in a bit of cold which means that you can plant them quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant primroses in Wilmette 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 grow to maturity. Starting your primroses indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Wilmette. You should expect an average low temperature of -15°F in the coldest months of winter.

Remember that USDA zone info for Wilmette is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Wilmette you get a frost after April 15 be ready to protect your primroses if you have a surprise late frost.

USDA Zone Info for Wilmette

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 Wilmette

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