One of the first steps you take when you are estimating your gardening schedule is find your 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.

One way of getting a good idea when it's a good idea to plant missouri primrose is to consult the USDA zone info for Zone 1a.

Planting Calendar for Missouri Primrose

Frost tolerance for missouri primrose:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Missouri Primrose are moderately cold tolerant which tells us that you can start planting them earlier than more sensitive plants.

The earliest that you can plant missouri primrose in Zone 1a is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant missouri primrose and expect a good harvest is probably July. Any later than that and your missouri primrose may not have a chance to really do well. If you are starting your missouri primrose indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost has passed is on June 15 in Zone 1a. In the coldest months of winter you can expect an average low temperature of -60°F.

Since the USDA zone info for Zone 1a may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in Zone 1a you get surprised by a frost after June 15 so be sure to be ready to cover your missouri primrose if you have one of those late frosts.

USDA Zone Info for Zone 1a

Here is the info for USDA Zone 1a.

Average Date of Last Frost (spring)	June 15
Average Date of First Frost (fall)	July 15
Lowest Expected Low	-60°F
Highest Expected Low	-55°F

This means that on a really cold year, the coldest it will get is -60°F. On most years you should be prepared to experience lows near -55°F.

Plants to Grow in Zone 1a

You may be interested in your other planting guides for Zone 1a.