One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

The first chance to plant primroses in Zone 4a should be estimated by checking out the USDA zone info.

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 cold weather which means that you can plant them a lot earlier in the year than more sensitive plants.

The earliest that you can plant primroses in Zone 4a is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant primroses and expect a good harvest is probably August. Any later than that and your primroses may not have a chance to grow to maturity. You can get started a little bit earlier by starting your primroses indoors.

Last Frost Date

On average the last frost is on May 15 in Zone 4a. It might get as low as -30°F during the coldest months of winter.

Since the USDA zone info for Zone 4a is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Zone 4a last frost occurs after May 15 so be sure to be ready to protect your primroses if you have a surprise late frost.

USDA Zone Info for Zone 4a

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Zone 4a

You may be interested in your other planting guides for Zone 4a.