One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of estimating when it's possible to plant primula is to refer to the USDA zone info for Estes Park.

Planting Calendar for Primula

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

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

The earliest that you can plant primula in Estes Park 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 primula and expect a good harvest is probably September. If you wait any later than that and your primula may not have a chance to really do well. You can get started a few weeks earlier by starting your primula indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Estes Park. You should expect an average low temperature of -20°F in the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Estes Park and it is different every year. Since half of the time in Estes Park it frosts late in the year after April 15 be ready to protect your primula if you have a surprise late frost.

USDA Zone Info for Estes Park

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 Estes Park

You may be interested in your other planting guides for Estes Park.