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.

It's possible to estimate when you can plant primula by reviewing the USDA zone info for Dickinson.

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 pretty solid cold which means that you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant primula in Dickinson 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 primula and expect a good harvest is probably August. You probably don't want to wait any later than that or else your primula may not have a chance to grow to maturity. You can get started a little bit earlier by starting your primula indoors.

Last Frost Date

In Dickinson the average date of last frost happens on May 15. In the coldest months of winter you should expect an average low temperature of -30°F.

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Dickinson and it can change quite a bit from year to year. Half of the time in Dickinson there is a last frost after May 15 so be sure to be ready to cover your primula in the event of one of those late frosts.

USDA Zone Info for Dickinson

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 Dickinson

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