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

A way of getting a good idea when it's the best time to plant primula is to look at the USDA zone info for Mount Prospect.

Planting Calendar for Primula

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

Primula do well in quite a bit of cold which means that 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 primula 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 primula and expect a good harvest is probably September. Any later than that and your primula may not have a chance to grow to maturity. Starting your primula indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Mount Prospect. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Mount Prospect is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Mount Prospect you get surprised by a frost after April 15 so be sure to be ready to protect your primula if you have a surprise 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.