When to Plant Primroses in Sterling, CO

One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant primroses in Sterling can be estimated by referring to the USDA zone info.


Planting Calendar for Primroses

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

Since primroses do well in cold you can plant them earlier in the year than other frost tender plants.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant primroses
Possibly ok, but a risky time to plant primroses
Probably not a good time to plant primroses

The earliest that you can plant primroses in Sterling 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. If you wait any later than that and your primroses may not have a chance to grow to maturity. Starting your primroses indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Sterling the average date of last frost happens on April 15. You can expect an average low temperature of -20°F in the coldest months of winter.

Since the USDA zone info for Sterling is an average the actual date of last frost changes from year to year. Since half of the time in Sterling last frost occurs after April 15 be ready to protect your primroses in the event of a late frost.

USDA Zone Info for Sterling

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-20°F
Highest Expected Low-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Sterling

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