One of the best tools that you have as gardeners to help us estimate 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 USDA zone info for Casper should be reffered to in order to figure out 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.

You can plant primroses a lot earlier in the year because they are very cold tolerant.

The earliest that you can plant primroses in Casper 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. You probably don't want to wait any later than that or else 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 few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Casper. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Casper may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Casper last frost occurs after April 15 be ready to protect your primroses in the event of one of those late frosts.

USDA Zone Info for Casper

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Casper

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