One of the best tools that you have as gardeners to help us figure out 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 to plant primroses by using the USDA zone info for Polson.

Planting Calendar for Primroses

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

Primroses do well in cold which tells us that you can get them planted much earlier than other plants that might not handle the cold.

The earliest that you can plant primroses in Polson 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. Any later than that and your primroses may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your primroses indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Polson. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Polson is not always accurate the actual date of last frost is different every year. Half of the time in Polson you get surprised by a frost after April 15 so make sure that you are prepared to cover your primroses in the event of one of those late frosts.

USDA Zone Info for Polson

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Polson

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