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.

The USDA zone info for Littleton should be reviewed to estimate when you can plant primroses.

Planting Calendar for Primroses

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

Primroses are very cold tolerant which means that you can plant them much earlier than other frost tender plants.

The earliest that you can plant primroses in Littleton 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 the last frost is on April 15 in Littleton. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Littleton is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Littleton it frosts late in the year after April 15 be ready to cover your primroses if you have a surprise late frost.

USDA Zone Info for Littleton

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Littleton

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