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.

You should be able to estimate when to plant primroses by reviewing the USDA zone info for Thomson.

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 earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

The earliest that you can plant primroses in Thomson 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 couple of weeks earlier by starting your primroses indoors.

Last Frost Date

On average all chance of frost has passed is on March 15 in Thomson. It might get as low as 10°F during the coldest months of winter.

It's important to remember that USDA zone info for Thomson is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Thomson it frosts late in the year after March 15 so be sure to be ready to protect your primroses in the event of a late frost.

USDA Zone Info for Thomson

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Thomson

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