Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You will be able to determine when to plant primula by using the USDA zone info for Merrill.

Planting Calendar for Primula

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

Primula can survive in cold weather which means that you can plant them quite a bit earlier in the year than more sensitive plants.

The earliest that you can plant primula in Merrill 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. Any later than that and your primula may not have a chance to really do well. You can get started a few weeks earlier by starting your primula indoors.

Last Frost Date

The average date of last frost is May 15 in Merrill. In the coldest months of winter you should expect an average low temperature of -30°F.

It's important to remember that USDA zone info for Merrill is an average and the actual date of last frost is different every year. Half of the time in Merrill you get surprised by a frost after May 15 so just be sure to be ready to cover your primula in the event of one of those late frosts.

USDA Zone Info for Merrill

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 Merrill

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